JP4143342B2 - toner - Google Patents

Description

【００５６】
また、モード円形度は、円形度を０．４０から１．００までを０．０１毎に６１分割し、測定した粒子の円形度をそれぞれの円形度に応じて各分割範囲に割り振り、円形度頻度分布において頻度値が最大となるピークの円形度である。
【００５７】
なお、本発明で用いている測定装置である「ＦＰＩＡ−１０００」は、各粒子の円形度を算出後、平均円形度及びモード円形度の算出に当たって、粒子を得られた円形度によって、円形度０．４０〜１．００を６１分割したクラスに分け、分割店の中心値と頻度を用いて平均円形度及びモード円形度の算出を行う算出法を用いている。しかしながら、この算出法で算出される平均円形度及びモード円形度の各値と、上述した各粒子の円形度を直接用いる算出式によって算出される平均円形度及びモード円形度の各値との誤差は、非常に少なく、実質的には無視できる程度のものであり、本発明においては、算出時間の短縮化や算出演算式の簡略化の如きデータの取り扱い上の理由で、上述した各粒子の円形度を直接用いる算出式の概念を利用し、一部変更したこのような算出法を用いても良い。
【００５８】
測定手順としては、以下の通りである。
【００５９】
界面活性剤約０．１ｍｇを溶解している水１０ｍｌに、トナー約５ｍｇを分散させて分散液を調整し、超音波（２０ｋＨｚ、５０Ｗ）を分散液に５分間照射し、分散液濃度を５０００〜２万個／μｌとして、前記装置により測定を行い、３μｍ以上の円相当径の粒子群の平均円形度及びモード円形度を求める。
【００６０】
本発明における平均円形度とは、トナーの凹凸の度合いの指標であり、トナーが完全な球形の場合１．０００を示し、トナーの表面形状が複雑になるほど平均円形度は小さな値となる。
【００６１】
なお、本測定において３μｍ以上の円相当径の粒子群についてのみ円形度を測定する理由は、３μｍ未満の円相当径の粒子群にはトナー粒子とは独立して存在する外部添加剤の粒子群も多数含まれるため、その影響によりトナー粒子群についての円形度が正確に見積もれないからである。
【００６２】
本発明のトナーは高画質化のため、より微小な潜像ドットを忠実に再現するため、トナーの重量平均粒径は３〜１０μｍであり、更には４〜９μｍであることがより好ましい。重量平均粒径が３μｍ未満のトナーにおいては、転写効率の低下から感光体上の転写残トナーが多くなり、接触帯電工程での感光体の削れやトナー融着の抑制が難しくなる。さらに、トナー全体の表面積が増えることに加え、粉体としての流動性及び撹拌性が低下し、個々のトナー粒子を均一に帯電させることが困難となることからハーフトーンの均一性が損なわれ、スリーブゴーストも生じやすくなり好ましくない。
【００６３】
一方、トナーの重量平均粒径が１０μｍを超える場合には、文字やライン画像に飛び散りが生じやすく、高解像度が得られにくい。さらに装置が高解像度になっていくと１０μｍ以上のトナーは１ドットの再現が悪化する傾向にある。
【００６４】
また、本発明のトナーは、重量平均粒径／数平均粒径の比が１．４０以下であることが重要であり、より好ましくは１．３５以下である。
【００６５】
重量平均粒径／数平均粒径の比が１．４０より大きいということはトナーの粒度分布が広いことを意味し、選択現像が生じやすくなってしまう。
【００６６】
ここで、トナーの平均粒径および粒度分布はコールターカウンターＴＡ−ＩＩ型あるいはコールターマルチサイザー（コールター社製）等種々の方法で測定可能であるが、本発明においてはコールターマルチサイザー（コールター社製）を用い、個数分布、体積分布を出力するインターフェイス（日科機製）及びＰＣ９８０１パーソナルコンピュータ（ＮＥＣ製）を接続し、電解液は１級塩化ナトリウムを用いて１％ＮａＣｌ水溶液を調整する。例えば、ＩＳＯＴＯＮ Ｒ−ＩＩ（コールターサイエンティフィックジャパン社製）が使用できる。
【００６７】
測定法としては、前記電界水溶液１００〜１５０ｍｌ中に分散剤として界面活性剤、好ましくはアルキルベンゼンスルフォン酸塩を０．１〜５ｍｌを加え、更に測定試料を２〜２０ｍｇ加える。試料を懸濁した電解液は超音波分散機で約１〜３分間分散処理を行い、前期コールターマルチサイザーによりアパーチャーとして１００μｍアパーチャーを用いて、２μｍ以上のトナー粒子の体積、個数を測定して体積分布と個数分布とを算出する。それから、体積分布から求めた体積基準の重量平均粒径（Ｄ４）、個数分布から求めた個数基準の長さ平均粒径、即ち数平均粒径（Ｄ１）を求める。後述の実施例においても同様に測定した。
【００６８】
本発明のトナーは離型剤を含有しているが、これまで述べたように離型剤の分散状態は現像性にも影響を与える。この為、本発明のトナーは、該トナーよりも重量平均粒径が小さいトナー（Ｆ）と、該トナーよりも重量平均粒径が大きいトナー（Ｇ）に２分割したとき、示差熱分析に（ＤＳＣ）測定における（Ｆ），（Ｇ）それぞれのトナーの吸熱量をＨｆ、Ｈｇとすると、０．６０＜Ｈｇ／Ｈｆ＜１．５０であることが好ましく、０．８０＜Ｈｇ／Ｈｆ＜１．２０であることがより好ましい。ここで、Ｈｇ／Ｈｆが１に近づくほど離型剤の分散性が良好であることを意味しており、このようなトナーは、本発明における前記処理ワックスを添加することにより得ることが出来る。
【００６９】
Ｈｇ／Ｈｆが０．６０より小さいトナーは離型剤の偏在が多く、離型剤を非常に多く含む粒子が存在することを意味する。このような粒子は、トナー表面への離型剤のしみ出しなどにより帯電の均一性が損なわれやすく、ゴーストを生じやすい。また、このようなトナーは長期使用においてトナー劣化を生じやすく好ましくない。
【００７０】
また、一般的に離型剤を含有するとトナーの帯電性は低下し、粒径の小さなトナーはチャージアップ傾向にあることも知られている。この為、Ｈｇ／Ｈｆが１．５０より大きいと、即ち、大粒径のトナーに離型剤が多く含まれるような場合、トナー全体として、均一な帯電性を有することが出来ず、ゴーストが生じやすくなる。
【００７１】
さらに、Ｈｇ／Ｈｆが１．５０より大きなものは、比較的大きな遊離の離型剤が存在することを意味する場合もあり、このような遊離の離型剤の存在は現像時に悪影響を及ぼすだけであり、この場合においてもスリーブゴーストの悪化、カブリの増大などを招き好ましくない。
【００７２】
このように、０．６０＜Ｈｇ／Ｈｆ＜１．５０とすることで、長期使用においても均一な帯電性を得ることが可能となり、ゴーストの無い高精細な画像を得ることが出来ると考えている。
【００７３】
これまで述べてきたように、粒度分布を特定の値とすることによる選択現像性の抑制と、離型剤の分散性、トナー形状を特定の値とすることによる帯電均一性の相乗効果で低湿環境下においてもスリーブゴーストが抑制でき、且つ、均一なハーフトーン画像を得ることが可能となる。
【００７４】
本発明のトナーには、荷電特性を安定化するために荷電制御剤を配合しても良い。荷電制御剤としては、公知のものが利用でき、特に帯電スピードが速く、且つ、一定の帯電量を安定して維持できる荷電制御剤が好ましい。さらに、トナーを直接重合法を用いて製造する場合には、重合阻害性が低く、水系分散媒体への可溶化物が実質的に無い荷電制御剤が特に好ましい。具体的な化合物としては、ネガ系荷電制御剤としてサリチル酸、アルキルサリチル酸、ジアルキルサリチル酸、ナフト工酸、ジカルボン酸の如き芳香族カルボン酸の金属化合物、アゾ染料あるいはアゾ顔料の金属塩または金属錯体、スルホン酸又はカルボン酸基を側鎖に持つ高分子型化合物、ホウ素化合物、尿素化合物、ケイ素化合物、カリックスアレーン等が挙げられる。ポジ系荷電制御剤として四級アンモニウム塩、該四級アンモニウム塩を側鎖に有する高分子化合物、グアニジン化合物、ニグロシン化合物、イミダゾール化合物等が挙げられる。
【００７５】
荷電制御剤をトナーに含有させる方法としては、トナー粒子内部に添加する方法と外添する方法がある。これらの荷電制御剤の使用量としては、結着樹脂の種類、他の添加剤の有無、分散方法を含めたトナー製造方法によって決定されるもので、一義的に限定されるものではないが、内部添加する場合は、好ましくは結着樹脂１００質量部に対して０．１〜１０質量部、より好ましくは０．１〜５質量部の範囲で用いられる。また、外部添加する場合、トナー１００質量部に対し、好ましくは０．００５〜１．０質量部、より好ましくは０．０１〜０．３質量部である。
【００７６】
しかしながら、本発明のトナーは、荷電制御剤の添加は必須ではなく、トナーの層圧規制部材やトナー担持体との摩擦帯電を積極的に利用することでトナー中に必ずしも荷電制御剤を含む必要は無い。
【００７７】
本発明のトナーは、粒度や着色剤及び離型剤含有量の異なるトナーを作製した後、混合する方法や、製造段階において着色剤及び離型剤の分散を異ならせる方法が考えられ、製造方法を特に限定するものではない。しかし、一般的に粉砕法で得られるトナー粒子は不定形のものであり、本発明に係わるトナーの必須条件である平均円形度が０．９７０以上という物性を得るためには、機械的・熱的あるいは何らかの特殊な処理を行うことが必要となり、生産性が劣るものとなる。そのため、本発明のトナーは分散重合法、会合凝集法、懸濁重合法など、水中で製造することが好ましい。また、結着樹脂が可溶な有機溶媒中に、結着樹脂、着色剤、離型剤、その他の添加剤を混合して油性成分を調整した後、該油性成分を水性媒体中に懸濁させ、粒子化して懸濁液を調整し、該懸濁液から有機溶媒を除去することにより本発明のトナーを製造することも好ましい形態の一つである。これらの中でも、特に懸濁重合法においては本発明の必須構成要件の諸物性を得やすく、非常に好ましい。
【００７８】
懸濁重合法とは、重合性単量体および着色剤（更に必要に応じて重合開始剤、架橋剤、荷電制御剤、その他の添加剤）を均一に溶解または分散させて重合性単量体系とした後、この重合性単量体系を分散安定剤を含有する連続層（例えば水相）中に適当な撹拌機を用いて分散し同時に重合反応を行わせ、所望の粒径を有するトナーを得るものである。この懸濁重合法で得られるトナー（以後重合トナー）は、個々のトナー粒子形状がほぼ球形に揃っているため、平均円形度が０．９７０以上、モード円形度が０９９以上という本発明に好適な物性要件を満たすトナーが得られやすく、さらにこういったトナーは帯電量の分布も比較的均一となるため高い転写性を有している。
【００７９】
本発明に関わる重合トナーの製造において、重合性単量体系を構成する重合性単量体としては以下のものが挙げられる。
【００８０】
重合性単量体としては、スチレン、ｏ−メチルスチレン、ｍ−メチルスチレン、ｐ−メチルスチレン、ｐ−メトキシスチレン、ｐ−エチルスチレン等のスチレン系単量体；アクリル酸メチル、アクリル酸エチル、アクリル酸ｎ−ブチル、アクリル酸イソブチル、アクリル酸ｎ−プロピル、アクリル酸ｎ−オクチル、アクリル酸ドデシル、アクリル酸２−エチルヘキシル、アクリル酸ステアリル、アクリル酸２−クロルエチル、アクリル酸フェニル等のアクリル酸エステル類；メタクリル酸メチル、メタクリル酸エチル、メタクリル酸ｎ−プロピル、メタクリル酸ｎ−ブチル、メタクリル酸イソブチル、メタクリル酸ｎ−オクチル、メタクリル酸ドデシル、メタクリル酸２−エチルヘキシル、メタクリル酸ステアリル、メタクリル酸フェニル、メタクリル酸ジメチルアミノエチル、メタクリル酸ジエチルアミノエチル等のメタクリル酸エステル類；その他のアクリロニトリル、メタクリロニトリル、アクリルアミド等の単量体が挙げられる。これらの単量体は単独、または混合して使用し得る。上述の単量体の中でも、スチレンまたはスチレン誘導体を単独で、あるいは他の単量体と混合して使用することがトナーの現像性及び耐久性の点から好ましい。
【００８１】
本発明に関わる重合トナーの製造においては、重合性単量体系に樹脂を添加して重合しても良い。例えば、単量体では水溶性のため水性懸濁液中では溶解して乳化重合を起こすため使用できないアミノ基、カルボン酸基、水酸基、スルホン酸基、グリシジル基、ニトリル基等、親水性官能基含有の重合性単量体成分をトナー中に導入したい時には、これらとスチレンあるいはエチレン等ビニル化合物とのランダム共重合体、ブロック共重合体、あるいはグラフト共重合体等、共重合体の形にして、あるいはポリエステル、ポリアミド等の重縮合体、ポリエーテル、ポリイミン等、重付加重合体の形で使用が可能となる。こうした極性官能基を含む高分子重合体をトナー中に共存させると、前述のワックス成分を相分離させ、より内包化が強力となり、耐ブロッキング性や現像性の良好なトナーを得ることができる。
【００８２】
これらの樹脂の中でも特にポリエステル樹脂を含有することにより、その効果は大きなものとなる。これは次に述べる理由からと考えている。ポリエステル樹脂は比較的極性の高い官能基であるエステル結合を数多く含むため、樹脂自身の極性が高くなる。その極性のため、水系分散媒中では液滴表面にポリエステルが偏在する傾向が強くなり、その状態を保ちながら重合が進行し、トナーとなる。この為、トナー表面にポリエステル樹脂が偏在する事で表面状態や、表面組成などが均一なものとなり、その結果帯電性が均一となると共に、離型剤の内包性が良好なこととの相乗効果により非常に良好な現像性を得ることが出来る。
【００８３】
また、材料の分散性や定着性、あるいは画像特性の改良等を目的として上記以外の樹脂を単量体系中に添加しても良く、用いられる樹脂としては、例えば、ポリスチレン、ポリビニルトルエンなどのスチレン及びその置換体の単重合体；スチレン−プロピレン共重合体、スチレン−ビニルトルエン共重合体、スチレン−ビニルナフタリン共重合体、スチレン−アクリル酸メチル共重合体、スチレン−アクリル酸エチル共重合体、スチレン−アクリル酸ブチル共重合体、スチレン−アクリル酸オクチル共重合体、スチレン−アクリル酸ジメチルアミノエチル共重合体、スチレン−メタアクリル酸メチル共重合体、スチレン−メタアクリル酸エチル共重合体、スチレン−メタアクリル酸ブチル共重合体、スチレン−メタクリル酸ジメチルアミノエチル共重合体、スチレン−ビニルメチルエーテル共重合体、スチレン−ビニルエチルエーテル共重合体、スチレン−ビニルメチルケトン共重合体、スチレン−ブタジエン共重合体、スチレン−イソプレン共重合体、スチレン−マレイン酸共重合体、スチレン−マレイン酸エステル共重合体などのスチレン系共重合体；ポリメチルメタクリレート、ポリブチルメタクリレート、ポリ酢酸ビニル、ポリエチレン、ポリプロピレン、ポリビニルブチラール、シリコーン樹脂、ポリエステル樹脂、ポリアミド樹脂、エポキシ樹脂、ポリアクリル酸樹脂、ロジン、変性ロジン、テルペン樹脂、フェノール樹脂、脂肪族または脂環族炭化水素樹脂、芳香族系石油樹脂などが単独或いは混合して使用できる。これら樹脂の添加量としては、重合性単量体１００質量部に対し１〜２０質量部が好ましい。１質量部未満では添加効果が小さく、一方２０質量部超添加すると重合トナーの種々の物性設計が難しくなる。
【００８４】
さらに、重合性単量体を重合して得られるトナーの分子量範囲とは異なる分子量の重合体を単量体中に溶解して重合すれば、分子量分布の広い、耐オフセット性の高いトナーを得ることが出来る。
【００８５】
本発明で使用される着色剤として、黒色着色剤としては、カーボンブラック、磁性体、イエロー／マゼンタ／シアン着色剤を用い黒色に調色されたものが利用される。
【００８６】
黒色着色剤として磁性体を用いる場合には、カップリング剤で疎水化処理されたものであることが好ましい。磁性体表面を疎水化する際、水系媒体中で、磁性体を一次粒径となるよう分散しながらカップリング剤を加水分解しながら表面処理することによって得られる磁性体が好適である。水系媒体中での疎水化処理方法は、気相中での処理に比べ、磁性体粒子同士の合一が生じにくく、また疎水化処理による磁性体粒子間の帯電反発作用が働き、磁性体はほぼ一次粒子の状態で表面処理されるようになるため、高い均一性の疎水化が達成されるので好ましい。
【００８７】
カップリング剤を水系媒体中で加水分解しながら磁性体表面を処理する方法は、クロロシラン類やシラザン類のようにガスを発生するようなカップリング剤を使用する必要もなく、さらに、これまで気相中では磁性体粒子同士が合一しやすくて、良好な処理が困難であった高粘性のカップリング剤も使用できるようになり、疎水化の効果は絶大である。
【００８８】
本発明に使用できるカップリング剤としては、例えば、シランカップリング剤、チタンカップリング剤が挙げられる。より好ましく用いられるのはシランカップリング剤であり、一般式
ＲｍＳｉＹｎ
［式中、Ｒはアルコキシ基を示し、ｍは１〜３の整数を示し、Ｙはアルキル基、ビニル基、グリシドキシ基、メタクリル基の如き炭化水素基を示し、ｎは１〜３の整数を示す。］
で示されるものである。例えばビニルトリメトキシシラン、ビニルトリエトキシシラン、γ−メタクリルオキシプロピルトリメトキシシラン、ビニルトリアセトキシシラン、メチルトリメトキシシラン、メチルトリエトキシシラン、イソブチルトリメトキシシラン、ジメチルジメトキシシラン、ジメチルジエトキシシラン、トリメチルメトキシシラン、ヒドロキシプロピルトリメトキシシラン、フェニルトリメトキシシラン、ｎ−ヘキサデシルトリメトキシシラン、ｎ−オクタデシルトリメトキシシランを挙げることができる。
【００８９】
特に、式
Ｃ_pＨ_2p+1−Ｓｉ−（ＯＣ_qＨ_2q+1）₃
［式中、ｐは２〜２０の整数を示し、ｑは１〜３の整数を示す］
で示されるアルキルトリアルコキシシランカップリング剤を使用して水系媒体中で磁性体を疎水化処理するのが良い。
【００９０】
上記式におけるｐが２より小さいと、疎水化処理は容易となるが、疎水性を十分に付与することが困難であり、またｐが２０より大きいと、疎水性は十分になるが、磁性体粒子同士の合一が多くなり、トナー中へ磁性体粒子を十分に分散させることが困難になる。
【００９１】
また、ｑが３より大きいと、シランカップリング剤の反応性が低下して疎水化が十分に行われにくくなる。特に、式中のｐが２〜２０の整数（より好ましくは、３〜１５の整数）を示し、ｑが１〜３の整数（より好ましくは、１又は２の整数）を示すアルキルトリアルコキシシランカップリング剤を使用するのが良い。
【００９２】
その処理量は磁性体１００質量部に対して、０．０５〜２０質量部、好ましくは０．１〜１０質量部であり、磁性体の表面積、カップリング剤の反応性などに応じて処理剤の量を調整することが好ましい。
【００９３】
本発明において、水系媒体とは、水を主要成分としている媒体である。具体的には、水系媒体として水そのもの、水に少量の界面活性剤を添加したもの、水にｐＨ調整剤を添加したもの、水に有機溶剤を添加したものが挙げられる。界面活性剤としては、ポリビニルアルコールの如きノンイオン系界面活性剤が好ましい。界面活性剤は、水に対して０．１〜５質量％添加するのが良い。ｐＨ調整剤としては、塩酸の如き無機酸が挙げられる。
【００９４】
撹拌は、例えば撹拌羽根を有する混合機（具体的には、アトライター、ＴＫホモミキサーの如き高剪断力混合装置）で、磁性体微粒子が水系媒体中で、一次粒子になるように充分におこなうのが良い。
【００９５】
こうして得られる磁性体粒子は粒子の凝集が見られず、表面が均一に疎水化処理されているため、トナー材料として用いた場合、トナー中への分散性が非常に良好であり、しかもトナー表面からの露出が無い。
【００９６】
また、本発明のトナーに用いられる磁性体は、鉄、リン、コバルト、ニッケル、銅、マグネシウム、マンガン、アルミニウム、珪素などの元素を含んでも良く、四三酸化鉄、γ−酸化鉄等、酸化鉄を主成分とするものであり、これらを１種または２種以上併用して用いられる。これら磁性体は、窒素吸着法によるＢＥＴ比表面積が２〜３０ｍ²／ｇが好ましく、特に３〜２８ｍ²／ｇがより好ましい。また、モース硬度が５〜７のものが好ましい。
【００９７】
本発明のトナーに用られる磁性体は、重合性単量体１００質量部に対して、１０〜２００質量部用いることが好ましく、２０〜１８０質量部用いることが更に好ましい。酸化鉄の配合量が１０質量部未満では現像剤の着色力が乏しく、カブリの抑制も困難であり、一方、２００質量部を超えると、現像剤担持体への磁力による保磁力が強まり現像性が低下したり、個々のトナー粒子への磁性体の均一な分散が難しくなるだけでなく、定着性が低下してしまう。
【００９８】
本発明のトナーをカラートナーとして用いた場合の着色剤としては、公知の染料または／及び顔料が使用される。例えば、カーボンブラック、フタロシアニンブルー、パーマネントブラウンＦＧ、ブリリアントファーストスカーレット、ピグメントグリーンＢ、ローダミン−Ｂベース、スルベントレッド４９、ソルベントレッド１４６、ソルベントブルー３５、キナクリドン、カーミン６Ｂ、ジスアゾエローなどが挙げられ、これらは単独でまたは２種類以上を混合して用いることができる。着色剤の使用量は、重合性単量体１００質量部に対して、２〜２５質量部程度であることが好ましい。
【００９９】
本発明のトナーの製造において使用される重合開始剤としては、重合反応時に半減期０．５〜３０時間であるものを、重合性単量体１００質量部に対し０．５〜２０質量部の添加量で重合反応を行うと、分子量１万〜１０万の間に極大を有する重合体を得、トナーに望ましい強度と適当な溶融特性を与えることができるので好ましい。
【０１００】
重合開始剤としては、従来公知のアゾ系重合開始剤、過酸化物系重合開始剤などがあり、アゾ系重合開始剤としては、２，２’−アゾビス−（２，４−ジメチルバレロニトリル）、２，２’−アゾビスイソブチロニトリル、１，１’−アゾビス（シクロヘキサン−１−カルボニトリル）、２，２’−アゾビス−４−メトキシ−２，４−ジメチルバレロニトリル、アゾビスイソブチロニトリル等が例示され、過酸化物系重合開始剤としてはｔ−ブチルパーオキシアセテート、ｔ−ブチルパーオキシラウレート、ｔ−ブチルパーオキシピバレート、ｔ−ブチルパーオキシ−２−エチルヘキサノエート、ｔ−ブチルパーオキシイソブチレート、ｔ−ブチルパーオキシネオデカノエート、ｔ−ヘキシルパーオキシアセテート、ｔ−ヘキシルパーオキシラウレート、ｔ−ヘキシルパーオキシピバレート、ｔ−ヘキシルパーオキシ−２−エチルヘキサノエート、ｔ−ヘキシルパーオキシイソブチレート、ｔ−ヘキシルパーオキシネオデカノエート、ｔ−ブチルパーオキシベンゾエート、α，α’−ビス（ネオデカノイルパーオキシ）ジイソプロピルベンゼン、クミルパーオキシネオデカノエート、１，１，３，３−テトラメチルブチルパーオキシ−２−エチルヘキサノエート、１，１，３，３−テトラメチルブチルパーオキシネオデカノエート、１−シクロヘキシル−１−メチルエチルパーオキシネオデカノエート、２，５−ジメチル−２，５−ビス（２−エチルヘキサノイルパーオキシ）ヘキサン、１−シクロヘキシル−１−メチルエチルパーオキシ−２−エチルヘキサノエート、ｔ−ヘキシルパーオキシイソプロピルモノカーボネート、ｔ−ブチルパーオキシイソプロピルモノカーボネート、ｔ−ブチルパーオキシ２−エチルヘキシルモノカーボネート、ｔ−ヘキシルパーオキシベンゾエート、２，５−ジメチル−２，５−ビス（ベンゾイルパーオキシ）ヘキサン、ｔ−ブチルパーオキシ−ｍ−トルオイルベンゾエート、ビス（ｔ−ブチルパーオキシ）イソフタレート、ｔ−ブチルパーオキシマレイックアシッド、ｔ−ブチルパーオキシ−３，５，５−トリメチルヘキサノエート、２，５−ジメチル−２，５−ビス（ｍ−トルオイルパーオキシ）ヘキサンなどのパーオキシエステル、ベンゾイルパーオキサイド、ラウロイルパーオキサイド、イソブチリルパーオキサイドなどのジアシルパーオキサイド、ジイソプロピルパーオキシジカーボネート、ビス（４−ｔ−ブチルシクロヘキシル）パーオキシジカーボネートなどのパーオキシジカーボネート、１，１−ジ−ｔ−ブチルパーオキシシクロヘキサン、１，１−ジ−ｔ−ヘキシルパーオキシシクロヘキサン、１，１−ジ−ｔ−ブチルパーオキシ−３，３，５−トリメチルシクロヘキサン、２，２−ジ−ｔ−ブチルパーオキシブタンなどのパーオキシケタール、ジ−ｔ−ブチルパーオキサイド、ジクミルパーオキサイド、ｔ−ブチルクミルパーオキサイドなどのジアルキルパーオキサイド、その他としてｔ−ブチルパーオキシアリルモノカーボネート等が挙げられ、必要に応じてこれらの開始剤を２種以上用いることもできる。
【０１０１】
本発明のトナーを製造する際には、架橋剤を添加してもよい。架橋剤の好ましい添加量としては、重合性単量体１００質量部に対して０．００１〜１５質量部である。
【０１０２】
ここで架橋剤としては、主として２個以上の重合可能な二重結合を有する化合物が用いられ、例えば、ジビニルベンゼン、ジビニルナフタレン等のような芳香族ジビニル化合物；例えばエチレングリコールジアクリレート、エチレングリコールジメタクリレート、１，３−ブタンジオールジメタクリレート等のような二重結合を２個有するカルボン酸エステル；ジビニルアニリン、ジビニルエーテル、ジビニルスルフィド、ジビニルスルホン等のジビニル化合物；及び３個以上のビニル基を有する化合物；が単独もしくは混合物として用いられる。
【０１０３】
本発明のトナーを重合法で製造する方法では、一般に上述のトナー組成物などを適宜加えて、ホモジナイザー、ボールミル、コロイドミル、超音波分散機等の分散機によって均一に溶解又は分散させた重合性単量体系を、分散安定剤を含有する水系媒体中に懸濁する。この時、高速撹拌機もしくは超音波分散機のような高速分散機を使用して一気に所望のトナー粒子のサイズとする方が、得られるトナー粒子の粒径がシャープになる。重合開始剤添加の時期としては、重合性単量体中に他の添加剤を添加するとき同時に加えても良いし、水系媒体中に懸濁する直前に混合しても良い。また、造粒直後、重合反応を開始する前に重合性単量体あるいは溶媒に溶解した重合開始剤を加えることも出来る。
【０１０４】
造粒後は、通常の撹拌機を用いて、粒子状態が維持され且つ粒子の浮遊・沈降が防止される程度の撹拌を行えばよい。
【０１０５】
本発明のトナーを製造する場合には、分散安定剤として公知の界面活性剤や有機分散剤・無機分散剤が使用できる。中でも無機分散剤は、有害な超微粉を生じ難く、その立体障害性により分散安定性を得ているので反応温度を変化させても安定性が崩れ難く、洗浄も容易でトナーに悪影響を与え難いので、好ましく使用できる。こうした無機分散剤の例としては、燐酸カルシウム、燐酸マグネシウム、燐酸アルミニウム、燐酸亜鉛等の燐酸多価金属塩、炭酸カルシウム、炭酸マグネシウム等の炭酸塩、メタ硅酸カルシウム、硫酸カルシウム、硫酸バリウム等の無機塩、水酸化カルシウム、水酸化マグネシウム、水酸化アルミニウム、シリカ、ベントナイト、アルミナ等の無機酸化物が挙げられる。
【０１０６】
これら無機分散剤を用いる場合には、そのまま使用しても良いが、より細かい粒子を得るため、水系媒体中にて該無機分散剤粒子を生成させて用いることが出来る。例えば、燐酸カルシウムの場合、高速撹拌下、燐酸ナトリウム水溶液と塩化カルシウム水溶液とを混合して、水不溶性の燐酸カルシウムを生成させることが出来、より均一で細かな分散が可能となる。この時、同時に水溶性の塩化ナトリウム塩が副生するが、水系媒体中に水溶性塩が存在すると、重合性単量体の水への溶解が抑制されて、乳化重合に依る超微粒トナーが発生し難くなるので、より好都合である。重合反応終期に残存重合性単量体を除去する時には障害となることから、水系媒体を交換するか、イオン交換樹脂で脱塩したほうが良い。無機分散剤は、重合終了後酸あるいはアルカリで溶解して、ほぼ完全に取り除くことが出来る。
【０１０７】
また、これらの無機分散剤は、重合性単量体１００質量部に対して、０．２〜２０質量部を単独で使用することが望ましいが、超微粒子を発生し難いもののトナーの微粒化はやや苦手であるので、０．００１〜０．１質量部の界面活性剤を併用しても良い。
【０１０８】
界面活性剤としては、例えばドデシルベンゼン硫酸ナトリウム、テトラデシル硫酸ナトリウム、ペンタデシル硫酸ナトリウム、オクチル硫酸ナトリウム、オレイン酸ナトリウム、ラウリル酸ナトリウム、ステアリン酸ナトリウム、ステアリン酸カリウム等が挙げられる。
【０１０９】
前記重合工程においては、重合温度は４０℃以上、一般には５０〜９０℃の温度に設定して重合を行う。この温度範囲で重合を行うと、内部に封じられるべき離型剤やワックスの類が、相分離により析出して内包化がより完全となる。残存する重合性単量体を消費するために、重合反応終期ならば、反応温度を９０〜１５０℃にまで上げる事は可能である。
【０１１０】
重合トナー粒子は重合終了後、公知の方法によって濾過、洗浄、乾燥を行い、必要により無機微粉体を混合し表面に付着させることで、本発明のトナーを得ることができる。また、製造工程に分級工程を入れ、粗粉や微粉をカットすることも可能である。
【０１１１】
本発明のトナー粒子には、流動性向上剤が外添されていることが画質向上のために好ましい。
【０１１２】
流動性向上剤としては、ケイ酸微粉体，酸化チタン，酸化アルミニウム等の無機微粉体が好ましい。該無機微粉体は、シランカップリング剤，シリコーンオイル又はそれらの混合物の如き疎水化剤で疎水化されていることが好ましい。
【０１１３】
トナー粒子がフルカラー画像形成用の非磁性のカラートナー粒子である場合は、外添剤として、酸化チタン微粒子を使用することが好ましい。
【０１１４】
流動性向上剤は通常、トナー粒子１００質量部に対して０．１〜５質量部使用される。
【０１１５】
トナー粒子と外添剤との混合は、ヘンシェルミキサーの如き混合機を用いるのが良い。
【０１１６】
本発明のトナーを二成分系現像剤に用いる場合は、トナーは磁性キャリアと混合して使用される。磁性キャリアとしては、例えば表面酸化又は未酸化の鉄、ニッケル、銅、亜鉛、コバルト、マンガン、クロム、希土類の如き金属粒子、それらの合金粒子、酸化物粒子及びフェライト等が使用できる。
【０１１７】
上記磁性キャリア粒子の表面を樹脂で被覆した被覆キャリアは、現像スリーブに交流バイアスを印加する現像法において特に好ましい。被覆方法としては、樹脂の如き被覆材を溶剤中に溶解もしくは懸濁せしめて調製した塗布液を磁性キャリアコア粒子表面に付着せしめる方法、磁性キャリアコア粒子と被覆材とを粉体で混合する方法等、従来公知の方法が適用できる。
【０１１８】
磁性キャリアコア粒子表面への被覆材料としては、シリコーン樹脂、ポリエステル樹脂、スチレン系樹脂、アクリル系樹脂、ポリアミド、ポリビニルブチラール、アミノアクリレート樹脂が挙げられる。これらは、単独或いは複数で用いる。
【０１１９】
本発明のトナーと磁性キャリアとを混合して二成分系現像剤を調製する場合、その混合比率は現像剤中のトナー濃度として、２〜１５質量％、好ましくは４〜１３質量％にすると通常良好な結果が得られる。トナー濃度が２質量％未満では画像濃度が低下しやすく、１５質量％を超えるとカブリや機内飛散が発生しやすい。
【０１２０】
次に、本発明のトナーを好適に用いることの出来る画像形成装置の一例を図に沿って具体的に説明する。
【０１２１】
画像形成装置として図３に示すような６００ｄｐｉのレーザービームプリンタ（キヤノン製：ＬＢＰ−８Ｍａｒｋ ＩＶ）を用意した。この装置は、プロセススピードが８０ｍｍ／ｓとなるように改造されている。図３に示すように、この装置は直流及び交流成分を印加した帯電ローラー５１を用い感光体５６を一様に帯電する。このとき、直流成分は定電圧に制御し、交流成分は定電流に制御する。なお、帯電ローラーの導電層は体積低効率が１０²Ω・ｃｍ、抵抗層は１０⁷Ω・ｃｍのものを用い、当接圧が２３０Ｎ／ｍとなるように設定した。帯電についで、レーザー光６０で画像部分を露光することにより静電潜像を形成し、一成分非磁性トナーにより可視画像としてトナー画像を形成した後、電圧を印加した転写ローラー（体積低効率が５×１０⁹Ω・ｃｍ）５７によりトナー画像を転写材５８に転写する。トナー画像をのせた転写材は定着器６３により転写材上に定着される。なお、感光体と転写ローラーとの当接圧力は線圧１３０Ｎ／ｍとなるように設定した。また、一部感光体上に残されたトナーはクリーニング部材５９としたウレタンゴムからなるブレードによりクリーニングされる。
【０１２２】
現像容器５２は図３に示すように、トナー供給体としてトナー担持体５４が感光体５６に当接されている。トナー担持体５４の表面の移動方向及び回転周速は、感光体ドラム表面との接触部分において同方向である。
【０１２３】
トナー担持体にトナーを塗布する手段として、現像部分に塗布ローラー５５が設けられ、該トナー担持体に当接している。接触部分において、塗布ローラー５５表面の移動方向が、トナー担持体の移動方向と反対方向に移動するように回転させることによりトナーをトナー担持体上に塗布する。さらに、該トナー担持体上トナーのコート層制御のために、樹脂コートしたステンレス製ブレード５３が取り付けられている。現像領域では、感光体５６とトナー担持体５４との間に直流の現像バイアスが印加され、トナー担持体上のトナーは静電潜像に応じて感光体５６上に飛翔し可視像となる。
【０１２４】
次に、フルカラー画像を形成するための画像形成方法の一例を図に基づいて説明する。
【０１２５】
図４は、複数画像形成部にて各色のトナー画像をそれぞれ形成し、これを同一転写材に順次重ねて転写するようにした画像形成装置である。ここでは、第１、第２、第３および第４の画像形成部２９_a，２９_b，２９_c，２９_dが並設されており、各画像形成部はそれぞれ専用の静電潜像保持体、所謂感光ドラム１９_a，１９_b，１９_c，および１９_dを具備している。感光ドラム１９_a乃至１９_dはその外周側に潜像形成手段２３_a，２３_b，２３_cおよび２３_d、現像部１７_a，１７_b，１７_cおよび１７_d、転写用放電部２４_a，２４_b，２４_cおよび２４_d、ならびにクリーニング部１８_a，１８_b，１８_cおよび１８_dが配置されている。このような構成にて、まず、第１画像形成部２９_aの感光ドラム１９_a上に潜像形成手段２３_aによって原稿画像における、例えばイエロー成分色の潜像が形成される。該潜像は現像手段１７_aのイエロートナーを有する現像剤で可視画像とされ、転写部２４_aにて、転写材としての記録材Ｓに転写される。上記のようにイエロー画像が転写材Ｓに転写されている間に、第２画像形成部２９_bではマゼンタ成分色の潜像が感光ドラム１９_b上に形成され、続いて現像手段１７_bのマゼンタトナーを有する現像剤で可視画像とされる。この可視画像（マゼンタトナー像）は、上記の第１画像形成部２９_aでの転写が終了した転写材Ｓが転写部２４_bに搬入されたときに、該転写材Ｓの所定位置に重ねて転写される。以下、上記と同様な方法により、第３、第４の画像形成部２９_c，２９_dによってシアン色、ブラック色の画像形成が行われ、上記同一の転写材Ｓに、シアン色、ブラック色を重ねて転写するのである。このような画像形成プロセスが終了したならば、転写材Ｓは定着部２２に搬送され、転写材Ｓ上の画像を定着する。これによって転写材Ｓ上には多色画像が得られるのである。転写が終了した各観光ドラム１９_a，１９_b，１９_cおよび１９_dはクリーニング部１８_a，１８_b，１８_cおよび１８_dにより残留トナーを除去され、引き続き行われる次の潜像形成のために供せられる。なお、上記画像形成装置では、転写材として記録材Ｓの搬送のために、搬送ベルト２５が用いられており、図４において、転写材Ｓは右側から左側へ搬送され、その搬送過程で、各画像形成部２９_a，２９_b，２９_cおよび２９_dにおける各転写部２４_a，２４_b，２４_cおよび２４_dを通過し、転写を受ける。この画像形成方法において、転写材を搬送する搬送手段として加工の容易性及び耐久性の観点からテトロン繊維のメッシュを用いた搬送ベルト及びポリエチレンテレフタレート系樹脂、ポリイミド系樹脂、ウレタン系樹脂の如き薄い誘電体シートを用いた搬送ベルトが利用される。転写材Ｓが第４画像形成部２９^dを通過すると、ＡＣ電圧が除電器２０に加えられ、転写材Ｓは除電され、ベルト２５から分離され、その後、定着器２２に入り、画像定着され、排出口２６から排出される。
【０１２６】
なお、この画像形成方法では、その画像形成部にそれぞれ独立した静電潜像保持体を具備しており、転写材はベルト式の搬送手段で、順次、各静電潜像保持体の転写部へ送られるように構成してもよい。また、この画像形成方法では、その画像形成部に共通する静電潜像保持体を具備してなり、転写材は、ドラム式の搬送手段で、静電潜像保持体の転写部へ繰り返し送られて、各色の転写を受けるように構成してもよい。
【０１２７】
次に、着色剤として磁性体を用いた磁性トナーを好適に用いることの出来る画像形成装置の一例を図に沿って具体的に説明する。
【０１２８】
図５において、１は感光ドラムで、その周囲に一次帯電ローラー５、現像器１０、転写帯電ローラー３、クリーナー４、給紙ローラー７等が設けられている。そして感光体ドラム１は一次帯電ローラー５によって−７００Ｖに帯電される（印加電圧は交流電圧−２．０ｋＶｐｐ、直流電圧−７００ＶＤＣ）。そして、レーザー発生装置６によりレーザー光１２を感光体ドラム１に照射することによって露光される。感光体ドラム１上の静電潜像は現像器１０によって一成分磁性トナーで現像され、転写材を介して感光体ドラム１に当接された転写帯電ローラー３により転写材上へ転写される。トナー画像をのせた転写材は搬送ベルト８等により定着器９へ運ばれ転写材上に定着される。また、一部感光体ドラム１上に残されたトナーはクリーナー４によりクリーニングされる。現像器１０は、図５に示すように感光体ドラム１に近接してアルミニウム、ステンレス等、非磁性金属で作られた円筒状のトナー担持体２（以下現像スリーブと称す）が配設され、感光体ドラム１と現像スリーブ２との間隙は図示されないスリーブ／感光体間隙保持部材等により約２３０μｍに維持されている。現像スリーブ内にはマグネットローラー（不図示）が現像スリーブ２と同心的に固定、配設されている。但し現像スリーブ２は回転可能である。マグネットローラーには複数の磁極が具備されており、それぞれ現像、トナーコート量規制、トナーの取り込み／搬送、トナーの吹き出し防止に影響している。現像スリーブ２に付着して搬送される磁性トナー量を規制する部材として、弾性ブレード１３が配設され弾性ブレード１３の現像スリーブ２に対する当接圧により現像領域に搬送されるトナー量が制御される。現像領域では、感光体ドラム１と現像スリーブ２との間に直流及び交流の現像バイアスが印加され、現像スリーブ２上トナーは静電潜像に応じて感光体ドラム１上に飛翔し可視像となる。
【０１２９】
・ＤＳＣ測定
示差走査熱量計（ＤＳＣ測定装置），ＤＳＣ−７（パーキンエルマー社製）を用いて以下のようにして測定する。
【０１３０】
測定試料は２〜１０ｍｇ、好ましくは５ｍｇを精密に秤量する。これをアルミパン中に入れ、リファレンスとして空のアルミパンを用い、測定温度範囲３０〜２００℃の間で、昇温速度１０℃／ｍｉｎで常温常湿下で測定を行う。この昇温過程で、温度３０〜２００℃の範囲におけるＤＳＣ曲線のメインピークの吸熱ピークが得られる。
【０１３１】
・ＧＰＣ測定
ゲルパーミエーションクロマトグラフィー（ＧＰＣ）によるクロマトグラムの分子量は次の条件で測定される。
【０１３２】
４０℃のヒートチャンバー中でカラムを安定化させ、この温度におけるカラムに溶媒としてテトラヒドロフラン（ＴＨＦ）を毎分１ｍｌの流速で流し、試料濃度として０．０５〜０．６質量％に調整した樹脂のＴＨＦ試料溶液を約５０〜２００μｌ注入して測定する。試料の分子量測定にあたっては、試料の有する分子量分布を数種の単分散ポリスチレン標準試料により作成された検量線の対数値とカウント数（リテンションタイム）との関係から算出する。検量線作成用の標準ポリスチレン試料としては、例えば東ソー社製或いはＰｒｅｓｓｕｒｅ Ｃｈｅｍｉｃａｌ Ｃｏ．製の分子量が６×１０²、２．１×１０³、４×１０³、１．７５×１０⁴、５．１×１０⁴、１．１×１０⁵、３．９×１０⁵、８．６×１０⁵、２×１０⁶、４．４８×１０⁶のものを用い、少なくとも１０点程度の標準ポリスチレン試料を用いるのが適当である。検出器にはＲＩ（屈折率）検出器を用いる。
【０１３３】
カラムとしては、１０³〜２×１０⁶の分子量領域を的確に測定するために、市販のポリスチレンジェルカラムを複数本組み合わせるのが良く、例えば昭和電工社製のｓｈｏｄｅｘ ＧＰＣ ＫＦ−８０１，８０２，８０３，８０４，８０５，８０６，８０７の組み合わせや、Ｗａｔｅｒｓ社製のμ−ｓｔｙｒａｇｅｌ ５００、１０³、１０⁴、１０⁵の組み合わせを挙げることができる。
【０１３４】
【実施例】
以下、本発明の具体的実施例について説明するが、本発明はこれらの実施例に限定されるものではない。以下の配合における部数は質量部である。
【０１３５】
（処理ワックスの製造法）
スチレンモノマー５２０ｇとノルマルブチルアクリレート１２０ｇに反応開始剤としてジクミルパーオキサイド８０ｇを添加した後、加熱溶融したパラフィンワックスＡ３２８０ｇ中に撹拌しながら滴下し、４時間反応させ、１段階の処理によって処理ワックス１を得た。
【０１３６】
ワックスの種類、スチレンモノマーの比率、不飽和カルボン酸系モノマーの種類や比率、加熱温度等を変え、同様に処理ワックスを得た。比率及び特性を表１、表２に示す。
【０１３７】
【表１】

【０１３８】
【表２】

【０１３９】
（疎水性磁性酸化鉄の製造法）
硫酸第一鉄水溶液中に、鉄イオンに対して１．０〜１．１当量の苛性ソーダ溶液を混合し、水酸化第一鉄を含む水溶液を調製した。該水溶液をｐＨ８に維持しながら、空気を吹き込み、８０〜９０℃で酸化反応を行い、種晶を生成させるスラリー液を調製した。次いで、このスラリー液に当初のアルカリ量（苛性ソーダのナトリウム成分）に対し０．９〜１．２当量となるよう硫酸第一鉄水溶液を加えた後、スラリー液をｐＨ＝８に維持して、空気を吹込みながら酸化反応を進め、酸化反応の終期にｐＨを約６に調整し、酸化反応を終了した。生成した酸化鉄粒子を洗浄、濾過して一旦取り出し、乾燥せずに別の水中に再分散させた後、再分散液のｐＨを調整し、十分撹拌しながらシランカップリング剤［ｎ−Ｃ₁₀Ｈ₂₁Ｓｉ（ＯＣＨ₃）₃］を磁性酸化鉄１００部に対し２部添加し、十分撹拌した。生成した疎水性酸化鉄粒子を常法により洗浄、濾過、乾燥し、次いで凝集している粒子を解砕処理し、疎水性磁性酸化鉄を得た。
【０１４０】
（トナー製造法）
トナー１の製造
イオン交換水７２０部に０．１Ｍ−Ｎａ₃ＰＯ₄水溶液４５０部、１Ｎ塩酸１９部を投入し６０℃に加温した後、１．０Ｍ−ＣａＣｌ₂水溶液６７．７部を添加して分散安定剤を含むｐＨ＝５．３の水系媒体を得た。
【０１４１】
スチレン ７８部
ｎ−ブチルアクリレート ２２部
ジビニルベンゼン ０．５部
飽和ポリエステル樹脂 ５部
負荷電制御剤（ジアルキルサリチル酸アルミ錯化合物） １部
カーボンブラック １０部
上記処方をアトライター（三井三池化工機（株））を用いて均一に分散混合した。この単量体組成物を６０℃に加温し、そこに処理ワックス１ １０部を添加混合溶解し、これに重合開始剤ｔ−ブチル−オキシ２−エチルヘキサノエート４質量部を溶解した。
【０１４２】
前記水系媒体中に上記重合性単量体系を投入し、６０℃，Ｎ₂雰囲気下においてＴＫ式ホモミキサー（特殊機化工業（株））にて１０，０００ｒｐｍで１５分間撹拌し、造粒した。その後パドル撹拌翼で撹拌しつつ、８０℃で８時間反応させた。反応終了後、懸濁液を冷却し、塩酸を加えてｐＨ＝２以下で分散剤を溶解し、分散剤を溶解し、濾過、水洗、乾燥してトナー粒子１を得た。
【０１４３】
このトナー粒子１００部と、一次粒径１２ｎｍのシリカにヘキサメチルジシラザンで処理をした後シリコーンオイルで処理し、処理後のＢＥＴ値が１２０ｍ²／ｇの疎水性シリカ微粉体１．０部をヘンシェルミキサー（三井三池化工機（株））を用い混合し、重量平均粒径が６．９μｍのトナー１を調製した。
【０１４４】
得られたトナー１、２００ｇを風力分級を行い（エルボージェット分級装置 ＥＪ−Ｌ−３：日鉄鉱業製）、トナー（Ｆ）を９８ｇトナー（Ｇ）を１０１ｇ得た。得られたトナー（Ｆ）、（Ｇ）それぞれについて離型剤の吸熱量の測定を行ったところ、Ｈｇ／Ｈｆは０．９８であった。トナー１の物性を表３に示す。
【０１４５】
トナー２〜４の製造
処理ワックス１を処理ワックス２〜４に変えたこと以外はトナー１の製造と同様にして、トナー２〜４を得た。トナー２〜４の物性を表３に示す。
【０１４６】
トナー５の製造
処理ワックス１を処理ワックス６に変えたこと以外はトナー１の製造と同様にして、トナー５を得た。トナー５の物性を表３に示す。
【０１４７】
トナー６の製造
処理ワックス１を処理ワックス８に変えたこと以外はトナー１の製造と同様にして、トナー６を得た。トナー６の物性を表３に示す。
【０１４８】
トナー７〜１０の製造
処理ワックス１を処理ワックス１１〜１４に変えたこと以外はトナー１の製造と同様にして、トナー７〜１０を得た。トナー７〜１０の物性を表３に示す。
【０１４９】
トナー１１の製造
処理ワックス１の量を０．７部としたこと以外はトナー１の製造と同様にしてトナー１１を得た。トナー１１の物性を表３に示す。
【０１５０】
トナー１２の製造
処理ワックス１の量を３１部としたこと以外はトナー１の製造と同様にしてトナー１２を得た。トナー１２の物性を表３に示す。
【０１５１】
トナー１３の製造
処理ワックス１を処理ワックス５に変えたこと以外はトナー１の製造と同様にして、トナー１３を得た。トナー１３の物性を表３に示す。
【０１５２】
トナー１４の製造
処理ワックス１を処理ワックス７に変えたこと以外はトナー１の製造と同様にして、トナー１４を得た。トナー１４の物性を表３に示す。
【０１５３】
トナー１５〜１６の製造
処理ワックス１を処理ワックス９〜１０に変えたこと以外はトナー１の製造と同様にして、トナー１５〜１６を得た。トナー１５〜１６の物性を表３に示す。
【０１５４】
トナー１７の製造
処理ワックス１を処理ワックス１５に変えたこと以外はトナー１の製造と同様にして、トナー１７を得た。トナー１７の物性を表３に示す。
【０１５５】
トナー１８の製造
処理ワックス１をパラフィンワックスＡに変えたこと以外はトナー１の製造と同様にして、トナー１８を得た。トナー１８の物性を表３に示す。
【０１５６】
トナー１９の製造
イオン交換水７２０部に０．１Ｍ−Ｎａ₃ＰＯ₄水溶液を２２６部、１Ｎ塩酸を１９部投入し６０℃に加温した後、１．０Ｍ−ＣａＣｌ₂水溶液３３．９部を添加して分散安定剤を含むｐＨ＝５．３水系媒体を得たこと以外はトナー１の製造と同様にして、トナー１９を得た。トナー１９の物性を表３に示す。
【０１５７】
トナー２０の製造
カーボンブラック１０部を疎水性磁性酸化鉄９０部に変えたこと以外はトナー１の製造と同様にして、トナー２０を得た。トナー２０の物性を表３に示す。
【０１５８】
トナー２１の製造
スチレン／ｎ−ブチルアクリレート共重合体 １００部
（質量比７８／２２）
飽和ポリエステル樹脂 ５部
負荷電制御剤（モノアゾ染料系のＦｅ化合物） ４部
カーボンブラック １０部
処理ワックス１ １０部
上記材料をブレンダーにて混合し、１１０℃に加熱した二軸エクストルーダーで溶融混練し、冷却した混練物をハンマーミルで粗粉砕し、粗粉砕物をジェットミルで微粉砕後、得られた微粉砕物を風力分級してトナー粒子２０を得た。このトナー粒子２０を１００部に対して、トナー１の製造で使用したシリカ１．０部をヘンシェルミキサーを用い混合し、重量平均粒径が８．４μｍのトナー２１を調製した。トナー２１の物性を表３に示す。
【０１５９】
トナー２２の製造
トナー２１の製造で得たトナー粒子２１をハイブリタイザーを用い、６０００回転で３分間の処理を２回行いトナー粒子２２を得た。このトナー粒子１００部に対してトナー１の製造で使用したシリカ１．０部を加え、ヘンシェルミキサーを用い混合しトナー２２を調整した。トナー２２の物性を表３に示す。
【０１６０】
トナー２３の製造
スチレン ６５部
２−エチルヘキシルアクリレート ３５部
ジビニルベンゼン ０．８部
カーボンブラック １０部
飽和ポリエステル樹脂 ８部
不飽和ポリエステル樹脂 ２部
上記処方をアトライターを用い均一に分散した。その後、６０℃に加温し、トナー１の製造で用いた処理ワックス１を１０部、２，２’−アゾビスイソブチロニトリル３．５部を添加し、溶解した。
【０１６１】
次いで、リン酸三カルシウム４質量％の水性コロイド溶液６５０部を６０℃に加温した後、上記の重合性単量体系１３４．３部を添加し、ＴＫホモミキサーを用いて室温にて、回転数１００００ｒｐｍで３分間乳化分散させた。
【０１６２】
その後、窒素雰囲気下にて撹拌を続けながら、８５℃で１０時間反応を行った後、室温まで冷却し、トナー粒子分散液を得た。
【０１６３】
次に、スチレン１３．０部、２−エチルヘキシルアクリレート７．０部、２，２’−アゾビスイソブチロニトリル０．４部、ジビニルベンゼン０．２部、ラウリル硫酸ナトリウム０．１部を水２０部に投入し、超音波ホモジナイザーを用い分散させ、水乳濁液４０．７部を得た。
【０１６４】
これを、前記トナー粒子分散液中に滴下し、粒子を膨潤させた。その後、窒素雰囲気下にて撹拌を行い、８５℃で１０時間反応を行った。その後、懸濁液を冷却し、トナー１と同様に洗浄、濾過、乾燥し、次いで風力分級を行いトナー粒子２３を得た。
【０１６５】
このトナー粒子２３を１００部と、トナー１の製造で使用したシリカ１．０部とをヘンシェルミキサーを用い混合し、重量平均粒径が７．８μｍのトナー２３を調製した。トナー２３の物性を表３に示す。
【０１６６】
【表３】

【０１６７】
〔実施例１〕
画像形成装置として、ＬＢＰ−８Ｍａｒｋ ＩＶを改造し、概ね図３に示されるものを用いた。
【０１６８】
静電荷像坦持体の電位は、暗部電位Ｖｄ＝−５８０Ｖ、明部電位ＶＬ＝−１５０Ｖとした。また、トナー担持体として、カーボンブラックを分散して抵抗を調節したシリコーンゴムからなる中抵抗ゴムローラ（直径１６ｍｍ、硬度ＡＳＫＥＲ Ｃ４５度、抵抗１０⁵Ω・ｃｍ）を用いて感光体に当接させた。このときの現像当接幅は約３ｍｍとなるようにした。該トナー担持体の周速は感光体周速（８０ｍｍ／ｓｅｃ）に対して順方向に１５０％のスピード（１２０ｍｍ／ｓｅｃ）とした。トナー塗布部材として発泡ウレタンゴムからなる塗布ローラーを設け、該トナー担持体に当接させた。塗布ローラーには、約−５５０Ｖの電圧を印加した。さらに、トナー規制部材として樹脂コートしたステンレス製ブレードを３９．２Ｎ／ｍ（４０ｇ／ｃｍ）の線圧で当接させた。また、現像時の印加電圧を直流成分（−４５０Ｖ）のみとした。
【０１６９】
帯電帯電時の印加電圧を直流成分（−１．２ｋＶ）、転写時の印加電圧を直流成分（−１．５ｋＶ）とした。
【０１７０】
最初に、トナー１をカートリッジに１００ｇ充填し、常温常湿環境下（２３℃，６０％ＲＨ）及び低温低湿環境下（１５℃，１０％ＲＨ）において、印字率３％の横線のみからなる画像パターンで６０００枚の画出し試験を行った。なお、転写材としては７５ｇ／ｍ²の紙を使用した。
【０１７１】
その結果、トナー１は初期、及び、６０００枚の画出し後において高い転写性を示し、ゴーストも無く、非画像部へのカブリのないハーフトーン再現性に優れた良好な画像が得られた。また、低温定着性、耐ホットオフセット性にも優れ、広い定着温度幅を取ることが出来た。常温常湿環境下での評価結果を表４に、低温低湿環境下での評価結果を表５に示す。
【０１７２】
本発明の実施例、ならびに、比較例中に記載の評価項目とその判断基準について述べる。
【０１７３】
＜定着温度幅＞
ＬＢＰ−８Ｍａｒｋ ＩＶの改造機を用いて定着試験を行った。このときの画像面積比率は２５％であり、単位面積当たりの、トナー載り量は、０．７ｍｇ／ｃｍ²に設定した。定着開始温度とオフセット開始温度の測定は、定着器の設定温度を１２０〜２１０℃迄の温度範囲で５℃おきに温度調節して、各々の温度で定着画像を出力し、得られた定着画像を４．９ｋＰａ（５０ｇ／ｃｍ²）の荷重をかけたシルボン紙で摺擦し、摺擦前後の濃度低下率が１０％以下となる定着温度を定着開始温度とした。また定着開始温度から更に設定温度を上げて行き、目視で高温オフセットの発生した温度をオフセット開始温度とした。
【０１７４】
＜転写効率＞
転写効率は、ベタ黒画像転写後の感光体上の転写残トナーをマイラーテープによりテーピングしてはぎ取り、紙上に貼ったもののマクベス濃度の値をＣ、転写後定着前のトナーの載った紙上にマイラーテープを貼ったもののマクベス濃度をＤ、未使用の紙上に貼ったマイラーテープのマクベス濃度をＥとした時、近似的に以下の式で計算した。
【０１７５】
【数２】

【０１７６】
上記の計算結果から得られた転写効率を以下の基準で判断した。
Ａ：転写効率が９６％以上。
Ｂ：転写効率が９２％以上、９６％未満。
Ｃ：転写効率が８９％以上、９２％未満。
Ｄ：転写効率が８９％未満。
【０１７７】
＜カブリ＞
カブリの測定は、東京電色社製のＲＥＦＬＥＣＴＭＥＴＥＲ ＭＯＤＥＬ ＴＣ−６ＤＳを使用して測定した。フィルターは、グリーンフィルターを用い、カブリは下記の式より算出した。
【０１７８】
カブリ（反射率）（％）＝
標準紙上の反射率（％）−サンプル非画像部の反射率（％）
【０１７９】
なお、カブリの判断基準は以下の通り。
Ａ：非常に良好（１．５％未満）
Ｂ：良好（１．５％以上乃至２．５％未満）
Ｃ：普通（２．５％以上乃至４．０％未満）
Ｄ：悪い（４％以上）
【０１８０】
＜ゴースト＞
ゴーストの判断基準は、図１に示す画像を出力し、以下の基準により目視で判断したものである。
Ａ：ゴーストは発生していない。
Ｂ：軽微なゴーストが発生しているものの、良好な画像。
Ｃ：ゴーストは発生しているものの、実用的には問題の無い画質。
Ｄ：ゴーストが悪く、実用上好ましくない画像。
【０１８１】
＜画質＞
画質の判断基準は、画像の均一性、細線再現性を総合的に評価したものである。なお、画像の均一性はベタ黒画像、ならびにハーフトーン画像の均一性で判断を行う。
Ａ：細線再現性、画像の均一性に優れ、鮮明な画像。
Ｂ：細線再現性、画像の均一性が若干劣るものの、良好な画像。
Ｃ：実用的には問題の無い画像。
Ｄ：細線再現性、画像の均一性が悪く、実用上好ましくない画像。
【０１８２】
〔実施例２、４、８〜１４、及び参考例３、５〜７〕
トナーとして、トナー２〜１２、２２、２３を使用し、実施例１と同様の条件で画出し試験及び耐久性評価を行った。その結果、初期の画像特性も問題なく、印字６０００枚までいずれも大きな問題の無い結果が得られた。常温常湿環境下での評価結果を表４に、低温低湿環境下での評価結果を表５に示す。
【０１８３】
〔実施例１５〕
画像形成装置として、ＬＢＰ−１７６０を改造し、概ね図５に示される構造のものを用いた。
【０１８４】
静電荷像担持体（感光体ドラム１）の電位は、暗部電位Ｖ_d＝−６５０Ｖ、明部電位Ｖ_L＝−１３０Ｖとした。また、静電荷像担持体と現像スリーブとの間隙は２７０μｍとし、トナー担持体として下記の構成の層厚約７μｍ、ＪＩＳ中心線平均粗さ（ＲＡ）１．０μｍの樹脂層を、表面をブラストした直径１６φのアルミニウム円筒上に形成した現像スリーブを使用し、現像磁極８５ｍＴ（８５０ガウス）、トナー規制部材として厚み１．０ｍｍ、自由長０．５ｍｍのウレタン製ブレードを３９．２Ｎ／ｍ（４０ｇ／ｃｍ）の線圧で当接させた。
フェノール樹脂 １００部
グラファイト（粒径約７μｍ） ９０部
カーボンブラック １０部
【０１８５】
次いで、現像バイアスとして直流バイアス成分Ｖ_dc＝−４５０Ｖ、重畳する交流バイアス成分Ｖ_p-p＝１６００Ｖ、Ｆ＝２２００Ｈｚを用いた。また、現像スリーブの周速は感光体周速（９４ｍｍ／ｓｅｃ）に対して順方向に１１０％のスピード（１０３ｍｍ／ｓｅｃ）とした。また、転写バイアスは直流１．５ｋＶとした。
【０１８６】
定着方法としては、ＬＢＰ−１７６０のオイル塗布機能のない、フィルムを介してヒーターにより加熱加圧定着する方式の定着装置を用いた。この時加圧ローラーはフッ素系樹脂の表面層を有するものを使用し、ローラーの直径は３０ｍｍであった。また、定着温度は１８０℃、ニップ幅を７ｍｍに設定した。
【０１８７】
定着温度幅の評価については、上記定着装置を用いたこと以外は実施例１と同様にして行った。
【０１８８】
トナー２０をカートリッジに１００ｇ充填し、常温常湿環境下（２３℃，６０％ＲＨ）及び低温低湿環境下（１５℃，１０％ＲＨ）において、印字率３％の横線のみからなる画像パターンで６０００枚の画出し試験を行った。なお、転写材としては７５ｇ／ｍ²の紙を使用した。
【０１８９】
その結果、トナー２０は初期、及び、６０００枚の画出し後において高い転写性を示し、ゴーストも無く、非画像部へのカブリのないハーフトーン再現性に優れた良好な画像が得られた。また、低温定着性、耐ホットオフセット性にも優れ、広い定着温度幅を取ることが出来た。常温常湿環境下での評価結果を表４に、低温低湿環境下での評価結果を表５に示す。
【０１９０】
〔比較例１〜８〕
トナーとして、トナー１３〜１９、２１を使用し、実施例１と同様の条件で画出し試験及び耐久性評価を行った。その結果、耐久試験と共に転写効率の低下、カブリ、ゴースト、画質の悪化が生じた。また、トナー１４、１５、１７については定着温度幅が狭かった。
【０１９１】
【表４】

【０１９２】
【表５】

【０１９３】
【発明の効果】
本発明のトナーを用いることにより、低温定着性、耐オフセット性に優れ、多数枚耐久においても良好なトナー性能が維持されると共に、ゴースト、カブリの無い高精細な画像を長期間安定して与えることが出来る。
【図面の簡単な説明】
【図１】画像上に発生するゴーストの概念図である。
【図２】高分子側のピーク面積▲１▼と低分子側のピーク面積▲２▼の概念図である。
【図３】本発明の実施に好適な画像形成装置の一例を示す図である。
【図４】フルカラー画像を形成するための画像形成方法の一例を示す図である。
【図５】磁性トナーを好適に用いることのできる画像形成装置の一例を示す図である。
【符号の説明】
５１ 帯電ローラー（接触帯電部材）
５２ 現像装置
５４ 現像スリーブ（トナー担持体）
５５ 撹拌部材
５６ 感光体（像担持体、被帯電体）
５７ 転写ローラー（転写部材）
５９ クリーナー
６３ 定着装置[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a toner for developing an electrostatic latent image in an image forming method such as an electrophotographic method, an electrostatic recording method, a magnetic recording method, and a toner jet method, an image forming method using the toner, and a process cartridge. About.
[0002]
[Prior art]
A number of methods are known as electrophotographic methods. In general, a photoconductive substance is used to form an electrical latent image on a photoreceptor by various means, and then the latent image is developed with toner. A visible image is formed and, if necessary, a toner image is transferred onto a transfer material such as paper. Then, the toner image is fixed on the transfer material by heat or pressure to obtain a copy. Further, the toner particles remaining on the photosensitive member without being transferred onto the transfer material are removed from the photosensitive member by the cleaning step, and the above-described steps are repeated.
[0003]
In recent years, such a copying apparatus has been strictly pursued for miniaturization, weight reduction, high speed, high resolution, and high reliability, and as a result, performance required for toner has become higher.
[0004]
As one means for satisfying this requirement, the toner particle size has been reduced, and Japanese Patent Laid-Open Nos. 1-112253, 1-191156, 2-214156, and 2-284158 are disclosed. Japanese Patent Laid-Open Nos. 3-181952 and 4-162048 propose toners having a specific particle size distribution and a small particle size.
[0005]
The most important performance required for toner in digital printers and high-definition image copying is fixing performance. Various methods and apparatuses have been developed for the fixing process, but the most common method at present is a thermocompression bonding method using a heat roller. This pressure heating method using a heating roller performs fixing by allowing the toner image surface of a fixing sheet to pass through the surface of a heat roller formed with a material having releasability with respect to the toner while being in contact with pressure. It is. In this method, since the surface of the heat roller and the toner image of the fixing sheet are brought into contact with each other under pressure, the thermal efficiency at the time of fusing the toner image on the fixing sheet is extremely good, and the fixing can be performed quickly. This is very effective in a high-speed electrophotographic copying machine.
[0006]
Conventionally, it has been known to include a wax as a release agent in a toner in order to improve offset resistance at low and high temperatures in fixing. For example, techniques such as JP-A-52-3304, JP-A-52-3305, and JP-A-57-52574 are disclosed. However, these waxes have improved offset resistance, but have deteriorated blocking resistance and developability.
[0007]
In recent years, it has been required to prevent the offset phenomenon, and at the same time, it is required to realize a fixing method with a short wait time and low power consumption. Therefore, a design that can realize fixing at a lower temperature is demanded. For example, JP-A-51-14333, JP-A-57-14852, JP-A-58-97056, JP-A-60-247250, JP-A-4-362953, JP-A-6-6- No. 230600 and JP-A-8-030036 use solid silicone varnish, higher fatty acid wax, higher alcohol wax, plant natural wax (carnauba, rice), montan ester wax as a release agent. Proposed.
[0008]
However, when such a wax, which is such a low softening point release agent, is contained in the toner as a release agent, it tends to adversely affect the development characteristics, chargeability, durability, and storage stability of the toner. Further, these waxes are difficult to uniformly disperse in the toner, and the wax that is free or unevenly distributed in the toner tends to adversely affect the developability and durability.
[0009]
JP-A-8-278657, JP-A-8-334919, and JP-A-8-334920 disclose two types of wax components in order to obtain a toner having excellent low-temperature fixability and offset resistance. Proposed to be included in toner. In JP-A-7-281478, a polypropylene resin and an acid-modified polyethylene resin are used as a release agent for toner in order to lower the minimum fixing temperature and increase the hot offset temperature. Proposed.
[0010]
Further, JP-A-58-63947, JP-A-63-191817, JP-A-9-73185, etc. propose a method of modifying polyolefin or polyethylene with a styrene monomer or an unsaturated carboxylic acid monomer. ing.
[0011]
However, using any of these release agents is just another way to achieve both low-temperature fixability, high-temperature offset resistance, and durability stability of the toner, and further improvements have been desired.
[0012]
On the other hand, as described above, as a recent technology direction, there has been a demand for a higher resolution and higher definition development method, and in order to respond to such a demand, progress has been made in the direction of reducing the particle size of the toner. However, as the toner particle size becomes smaller, the uniform dispersion of the release agent becomes an important technique. That is, unless a uniform amount of the release agent is uniformly contained in fine individual toner particles, the image characteristics and the stability thereof are more likely to be deteriorated. This is because the toner particle size is simply reduced, and the adhesion force (mirror power, van der Waals force, etc.) of the toner particles to the photoconductor is larger than the Coulomb force applied to the toner particles in the transfer process. As a result, in addition to an increase in the residual toner, a decrease in the toner particle size is inevitably accompanied by an increase in charge amount and a deterioration in fluidity, so that a difference in dispersibility tends to appear as a large difference in physical properties. This is because the ratio of fog and toner with poor transferability increases. Also, those having poor dispersibility of the release agent and those having a large amount of free release agent tend to have a non-uniform charge amount on the toner and are likely to cause selective development. This will cause the development of unevenness called shading. Furthermore, it is difficult for such a toner to obtain a uniform image, particularly as a halftone image, and such a phenomenon is likely to occur remarkably in a low-humidity environment where a difference in chargeability tends to occur.
[0013]
Conventional toners are manufactured as a toner having a desired particle size (pulverization method) after melt-kneading a binder resin, colorant, etc., uniformly dispersing, then pulverizing with a fine pulverizer, and classifying with a classifier. However, there is a limit to the material selection range for the toner particle size reduction. For example, the resin colorant dispersion must be sufficiently brittle and capable of being finely pulverized with an economically usable production device. From this requirement, in order to make the resin colorant dispersion brittle, when the resin colorant dispersion is actually finely pulverized at a high speed, particles having a wide particle size range are easily formed, and in particular, a relatively large proportion of fine particles ( There arises a problem that excessively pulverized particles) are included therein. Further, such highly brittle materials are often further pulverized or powdered when used as developing toners in copying machines and the like.
[0014]
Also, in the pulverization method, as described above, since the compatibility between the binder resin and the release agent is poor, it is difficult to completely and uniformly disperse the release agent in the resin, and the dispersibility is poor. Tends to have many release agents on the differential side, which causes ghosting and increases fogging and decreases image density. Further, in the pulverization method, a free release agent is easily generated, and problems still remain in the fluidity of the toner and the charging stability in a harsh environment.
[0015]
On the other hand, in recent years, many technical disclosures have been made regarding toners by polymerization (hereinafter referred to as polymerized toners). Compared with the pulverization method, the polymerization method can easily make toner fine particles, and further, since the obtained toner has a spherical shape, it has excellent fluidity and is considered to be advantageous for high image quality.
[0016]
However, even in the polymerization method, the release agent component in the polymerizable monomer is in an agglomerated state, and the amount of the release agent component in each produced toner varies, or the release agent is in the center of the toner. No toner that can satisfy the charging characteristics, fixing properties, fluidity, and anti-blocking properties of individual toners has been obtained.
[0017]
In order to solve the above problems, in Japanese Patent No. 2744335, a polymerizable composition comprising a polymerizable monomer, an unmodified wax (low molecular weight polyolefin), and a graft modified wax (polyolefin grafted resin), There has been proposed a method for producing a toner which is heated once to dissolve the unmodified wax, then cooled to finely disperse the unmodified wax in the polymerizable composition, and then subjected to suspension polymerization. In JP-A-5-303232, the carbon black graft polymer and the wax are kneaded to disperse the wax in the carbon black graft polymer matrix and then uniformly in the polymerizable monomer. There is a technical disclosure regarding a method for producing colored fine particles that are dispersed and suspension polymerized.
[0018]
However, as a result of studies by the present inventors, even when the above-described wax and method are used, offset resistance and fixing ability can be improved to some extent, but it is possible to sufficiently prevent generation of free wax. Therefore, the toner does not satisfy the chargeability, durability, and environmental stability required for high-definition images. In addition, the above-described method is not preferable because the process becomes complicated, such as once the wax is heated and melted and cooled and precipitated, leading to an increase in cost and a decrease in productivity.
[0019]
[Problems to be solved by the invention]
An object of the present invention is to provide a toner having excellent low-temperature fixability and offset resistance, high transfer efficiency, and low fog. It is another object of the present invention to provide a toner capable of obtaining a high-quality image with a uniform halftone and no ghost even when used for a long time.
[0020]
[Means for Solving the Problems]
The object of the present invention is achieved by the following.
[0021]
  That is, a toner having a weight average particle diameter of 3 to 10 μm containing at least a binder resin, a colorant, and a release agent,
  The toner has an average circularity of 0.970 or more;
  The endothermic peak in the differential thermal analysis (DSC) measurement of the release agent is in the range of 45-120 ° C;
  The release agent was treated with at least a styrenic monomer.paraffinIt is a wax (hereinafter referred to as a treated wax), and this treated wax has two peaks as measured by gel permeation chromatography (GPC) of the soluble content of tetrahydrofuran (THF), and has a peak on the polymer side. When the area is (1) and the area of the low-molecular peak is (2), the area ratio is
    0.2 ≦ (2) / ((1) + (2)) <0.5 (Formula 1)
The toner satisfies the following conditions.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail with reference to preferred embodiments of the present invention. The present inventors have found that the above-mentioned problems can be achieved by using a treated wax treated with at least a styrenic monomer as a release agent which is a raw material of toner. Usually, the hydrocarbon wax has a weak interfacial adhesive force with the toner resin, and a free wax is easily generated. The free hydrocarbon wax was fused to the cleaning blade and the photosensitive member, and the developability and the cleaning property were deteriorated. In addition, self-aggregation and adhesion are high, and the fluidity of the toner deteriorates. For this reason, problems such as a decrease in the rising speed of charging, fogging due to charging failure, developing unit sleeve contamination, and carrier contamination in two-component development have occurred.
[0023]
Therefore, the present inventors considered that the hydrocarbon wax is treated so as to be easily compatible with the toner resin component, thereby improving the interfacial adhesive force and preventing detachment. As a result of diligent investigation, a hydrocarbon wax treated with at least a styrenic monomer for compatibility with the binder resin, dispersibility when incorporated in the toner, fluidity, developability and fixability I found it the most effective way. The details of this effect are not clear, but it is probably because of the following reasons.
[0024]
The treated wax of the present invention uses a styrenic monomer, but the molecular structure of the binder resin is similar to the portion of the hydrocarbon wax modified by the treatment in which a copolymer mainly composed of the styrenic monomer is formed. For this reason, it is considered that the compatibility with each other is increased and the desorption of the wax is less likely to occur. As a result, the wax was not fused to the cleaning blade or the photosensitive member, charging failure, and the like, and excellent developability and cleanability without fogging could be maintained.
[0025]
The treated wax used in the present invention will be described.
[0026]
The treated wax used in the present invention can be a hydrocarbon wax treated with a styrene monomer, and a hydrocarbon wax treated with a styrene monomer and an unsaturated carboxylic acid monomer can also be preferably used. The treated wax functions as a release agent in the toner.
[0027]
As the hydrocarbon wax before treatment, a hydrocarbon wax having a softening point of 45 to 120 ° C. can be preferably used, and paraffin hydrocarbon wax is particularly preferable. As the paraffin hydrocarbon wax, known paraffin wax, synthetic paraffin wax, microcrystalline wax, Fischer-Tropsch wax and the like can be used.
[0028]
Examples of the styrene monomer include styrene, α-methyl styrene, vinyl toluene, isopropenyl toluene, p-methyl styrene, p-methoxy styrene, m-methyl styrene and the like.
[0029]
Examples of unsaturated carboxylic acid monomers include methyl acrylate, ethyl acrylate, butyl acrylate, sec-butyl acrylate, isobutyl acrylate, propyl acrylate, isopropyl acrylate, 2-octyl acrylate, dodecyl acrylate, acrylic Stearyl acid, hexyl acrylate, isohexyl acrylate, phenyl acrylate, 2-chlorophenyl acrylate, diethylaminoethyl acrylate, 3-methoxybutyl acrylate, diethylene glycol ethoxylate acrylate, 2,2,2-trifluoroethyl acrylate Acrylic acid esters such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, isobutyl methacrylate, propyl methacrylate, methacrylic acid Sopropyl, 2-octyl methacrylate, dodecyl methacrylate, stearyl methacrylate, hexyl methacrylate, decyl methacrylate, phenyl methacrylate, 2-chlorohexyl methacrylate, diethylaminoethyl methacrylate, 2-hexylethyl methacrylate, methacrylic acid 2 , 2,2-trifluoroethyl and the like; and other maleates such as ethyl maleate, propyl maleate, butyl maleate, diethyl maleate, dipropyl maleate and dibutyl maleate; fumaric acid Examples thereof include fumaric acid esters such as ethyl, butyl fumarate and dibutyl fumarate, and itaconic acid esters such as ethyl itaconate, diethyl itaconate and butyl itaconate.
[0030]
The treated wax of the present invention can treat a hydrocarbon wax according to a usual method and conditions using a styrene monomer or an unsaturated carboxylic acid monomer. Specifically, for example, a method using radiation or a method using a radical catalyst can be used, but a method using a radical catalyst is preferable.
[0031]
As radical catalysts, organic peroxides, organic peroxides such as benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di (peroxidebenzoate) hexyne-3 1,4-bis (tert-butylperoxyisopropyl) benzene, lauroyl peroxide, tert-butyl peracetate, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne-3,2,5-dimethyl -2,5-di (tert-butylperoxy) hexane, tert-butyl perbenzoate, tert-butyl perphenyl acetate, tert-butyl perisobutyrate, tert-butyl per-sec-octate, ter - butyl perpivalate, cumyl perpivalate and tert- butyl hydroperoxide diethyl acetate; other azo compounds such as azobisisobutyronitrile, and the like dimethyl azoisobutyrate. Among these, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne-3, 2,5-dimethyl-2,5-di (tert- Dialkyl peroxides such as butylperoxy) hexane and 1,4-bis (tert-butylperoxyisopropyl) benzene are preferred.
[0032]
As a monomer selection, when treating with a styrene monomer alone, two or more styrene monomers are used. When treating with a styrene monomer and an unsaturated carboxylic monomer, two or more styrene monomers are used, an unsaturated carboxylic acid. A method of selecting two or more types of monomers may be used, and there is no limitation to the number of monomers selected. Also, there is no limitation on the order in which the monomers are treated. For example, a method of treating a styrene monomer and an unsaturated carboxylic acid monomer simultaneously with paraffin, a method of treating an unsaturated carboxylic acid monomer after treating the styrene monomer. and so on.
[0033]
  The treated wax used in the present invention is treated with a styrene-based monomer alone or with a styrene-based monomer and an unsaturated carboxylic acid-based monomer, and has two peaks in the molecular weight measurement by GPC of the THF soluble content of the treated wax. ing. It is a peak on the polymer side(1)Is the peak of the modified wax modified with the monomer, the peak on the low molecular side(2)Is the peak of slightly modified or unmodified wax. From the viewpoint of fixability, it is preferable that an unmodified wax is present.(1)The peak area of(2)The peak area of
    0.2 ≦(2) /((1)+(2)) ≦ 0.8 (Formula 1)
Is preferred, but more preferably 0.2 ≦(2)/ ((1)+(2)) <0.5.
[0034]
  (2)/ ((1)+(2)) Greater than 0.8, the compatibility between the wax and the binder resin is low, so that a free wax is easily generated, which is disadvantageous in terms of developability and durability.(2)/ ((1)+(2)) Is less than 0.2, the dispersion of the wax in the toner becomes very good, but on the contrary, the seepage of the wax becomes disadvantageous at the time of fixing, and the fixing temperature width becomes small.
[0035]
  (1)as well as(2)As shown in FIG. 2, the peak area is divided by a line drawn vertically from the inflection point of the GPC molecular weight distribution curve to the horizontal axis, and the area on the polymer side is(1), The area on the low molecule side(2)It was.
[0036]
  Furthermore, molecular weight measurement by GPC of the THF soluble content of the treated wax of the present invention(1)Number average molecular weight (Mn(1)) Is 8,000 or less,(2)Number average molecular weight (Mn(2)) Preferably satisfies 200 or more. Mn(1)When the value is larger than 8,000, the releasability of the modified wax is lost and the fixing temperature range is narrowed. Mn(2)Is less than 200, the high temperature offset resistance and toner storage stability during fixing deteriorate.
[0037]
  Furthermore, the following formula
    1,000 ≦ (Mn(1)-Mn(2)) ≦ 6,000 (Formula 2)
It is desirable that
[0038]
  Where (Mn(1)-Mn(2)) Represents the approximate number average molecular weight of the portion modified with the modified wax monomer. (Mn(1)-Mn(2)) Is less than 1,000, the molecular weight of the polymer portion is too small, so that the storage stability is deteriorated when the toner is formed. (Mn(1)-Mn(2)) Exceeds 6,000, the molecular weight of the copolymer portion is too large, so that the wax exudes during fixing and the effect as a release agent is lost.
[0039]
  Furthermore, the treated wax of the present invention has a Mn molecular weight measured by GPC of THF soluble content.(2)Is the following formula
    200 ≦ Mn(2)<2000
And the molecular weight is Mn in the molecular weight measurement by GPC of the THF soluble part of the treated wax.(2)Assuming that the amount of the wax component modified with the monomer is A and the amount of the unmodified wax component is B, the following formula:
    0.08 ≦ {B / (A + B)} × {(2)/ ((1)+(2))} ≦ 0.78
It is preferable to satisfy
    0.1 ≦ {B / (A + B)} × {(2)/ ((1)+(2))} ≦ 0.78
Is more preferable.
[0040]
  Here, the values of A and B are the peaks on the high molecular weight side when the GPC curve of the treated wax is separated into two by Gaussian distribution approximation.(1)’, The lower molecular weight peak(2)'age,(1)'When(2)The area of the overlapping portion of ‘(2)The area of ′ was B.
[0041]
  In general, from the viewpoint of low-temperature fixability, it is advantageous to lower the molecular weight and softening point. In the present invention, the molecular weight of the untreated wax is 200 ≦ Mn.(2)<2000 is preferable. However, at this time, {B / (A + B)} × {(2)/ ((1)+(2))} Is greater than 0.78,(1)'When(2)This means that there is almost no overlapping part A ', which means that the treated wax consists only of unmodified wax and almost completely modified wax. Mn(2)When the molecular weight becomes as low as 2000 or less, the unmodified wax is very soft and has strong self-aggregation property, so that dispersion in the binder resin tends to be further deteriorated. On the other hand, since the modified wax has a very high compatibility with the binder resin, the compatibility with the unmodified wax is relatively lowered, and the modified wax is used as a compatibilizer or dispersant for the unmodified wax. It cannot function and as a result, detachment of the unmodified wax occurs. Conversely, {B / (A + B)} × {(2)/ ((1)+(2))} Is less than 0.08, the unmodified wax is not detached, but the proportion of the copolymer portion is increased, and the wax exudes during fixing, which is disadvantageous for low-temperature fixability.
[0042]
The treated wax of the present invention is obtained in one step by treating a hydrocarbon wax with a monomer, and contains a wax component having various degrees of modification and an unmodified wax component. For this reason, even when a low molecular weight wax is used aiming at low-temperature fixability, the unmodified wax component does not desorb and the high compatibility with the binder resin component is maintained and uniformly dispersed. It is considered possible.
[0043]
In the treated wax of the present invention, the total amount of monomers to be treated is preferably 5 to 100 parts by mass with respect to 100 parts by mass of the hydrocarbon wax. If the total amount of monomers is 5 parts by mass or less, the effect as a processing wax cannot be obtained, which is disadvantageous for wax fusion of the cleaning blade or the photoreceptor, a decrease in the rising speed of charging, charging failure, sleeve, carrier contamination, etc. become. When the total amount of monomers is 100 parts by mass or more, the speed of wax exudation at the time of fixing the treated wax decreases, and the fixing property becomes disadvantageous.
[0044]
Moreover, when using together a styrene-type monomer and an unsaturated carboxylic acid-type monomer, it is preferable that (the styrene-type monomer mass part / mass part number of an unsaturated carboxylic acid-type monomer) is 1-20. If (styrene part by mass / part by mass of unsaturated carboxylic acid monomer) is greater than 20, the softening point of the treated wax tends to increase, which is not preferable because the amount of the monomer to be treated is limited. When (mass part of styrene monomer / mass part of unsaturated carboxylic acid monomer) is less than 1, the effect of compatibility with the binder resin by treating the wax cannot be sufficiently obtained, and the dispersibility in the toner is not obtained. Decreases and charging stability becomes disadvantageous. In addition, toner storage stability is also deteriorated.
[0045]
The release agent of the present invention preferably has a main peak value in the DSC endothermic curve of 45 to 120 ° C, more preferably 50 to 90 ° C. This peak value represents the softening point of the treated wax, and if the peak value is 45 ° C. or lower, the storage stability of the toner is deteriorated. Further, when the peak value is 120 ° C. or higher, the low-temperature fixability of the toner is deteriorated.
[0046]
The treated wax used in the present invention is preferably 1 to 30 parts by mass with respect to 100 parts by mass of the resin component in the toner. If it is less than 1 part by mass, the effect of the treated wax as a release agent is lost, and the temperature range of fixing is reduced. If it exceeds 30 parts by mass, the toner itself is softened, and durability is disadvantageous.
[0047]
For DSC measurement, for example, DSC-7 manufactured by PerkinElmer is used. The temperature correction of the device detection unit uses the melting points of indium and zinc, and the correction of heat uses the heat of fusion of indium.
[0048]
The measurement sample is precisely weighed in an amount of 2 to 10 mg, preferably 5 mg. This is put in an aluminum pan, and an empty aluminum pan is used as a reference, and measurement is performed at a temperature rise rate of 10 ° C./min at room temperature and normal humidity within a measurement temperature range of 30 to 200 ° C. In this temperature raising process, an endothermic peak of the main peak of the DSC curve in the temperature range of 30 to 200 ° C. is obtained.
[0049]
The average circularity of the toner of the present invention is 0.970 or more. When the average circularity of the toner is 0.970 or more, the toner can form uniform and narrow spikes at the developing portion and can develop faithfully with respect to the latent image, and an improvement in image quality can be expected.
[0050]
Further, since such toners have a relatively uniform toner shape, charging is likely to be uniform and effective in suppressing sleeve ghosts.
[0051]
Further, when the average circularity is 0.970 or more, the toner transferability is very good. This is thought to be because the contact area between the toner particles and the photoconductor is small, and the adhesion force of the toner particles to the photoconductor due to the mirror force, van der Waals force, or the like is reduced.
[0052]
Further, in the circularity distribution of the toner, when the mode circularity is 0.99 or more, it means that most of the toner particles have a shape close to a true sphere, and the above action becomes more remarkable. preferable.
[0053]
In such a nearly spherical toner, the entire toner particle surface may come into contact with the toner carrier, the photoreceptor surface, etc., but the dispersion state in the toner is controlled by using the treated wax of the present invention. As a result, durability is further improved, and high developability can be maintained even during long-term use.
[0054]
The average circularity in the present invention is used as a simple method for quantitatively expressing the shape of the particles. In the present invention, the flow type particle image analyzer “FPIA-1000” manufactured by Toa Medical Electronics is used. Measurement was performed, and the circularity (Ci) of each particle measured for a particle group having a circle-equivalent diameter of 3 μm or more was determined by the following equation (5), and further measured by the following equation (6). The value obtained by dividing the sum of the circularity by the total number of particles (m) is defined as the average circularity (C).
[0055]
[Expression 1]

[0056]
In addition, the mode circularity is obtained by dividing the circularity from 0.40 to 1.00 into 61 units every 0.01, and assigning the measured particle circularity to each divided range according to each circularity. This is the circularity of the peak having the maximum frequency value in the frequency distribution.
[0057]
In addition, “FPIA-1000”, which is a measuring apparatus used in the present invention, calculates the circularity of each particle and then calculates the average circularity and the mode circularity. A calculation method is used in which 0.40 to 1.00 is divided into 61 classes, and the average circularity and mode circularity are calculated using the center value and frequency of the divided stores. However, an error between each value of the average circularity and the mode circularity calculated by this calculation method and each value of the average circularity and the mode circularity calculated by the calculation formula that directly uses the circularity of each particle described above. Is very small and practically negligible.In the present invention, for the reasons of data handling such as shortening the calculation time and simplifying the calculation formula, Such a calculation method that is partially changed by using the concept of a calculation formula that directly uses the circularity may be used.
[0058]
The measurement procedure is as follows.
[0059]
A dispersion is prepared by dispersing about 5 mg of toner in 10 ml of water in which about 0.1 mg of a surfactant is dissolved. The dispersion is irradiated with ultrasonic waves (20 kHz, 50 W) for 5 minutes, and the concentration of the dispersion is 5000. Measurement is performed with the above apparatus at 20,000 / μl, and the average circularity and mode circularity of a particle group having a circle-equivalent diameter of 3 μm or more are obtained.
[0060]
The average circularity in the present invention is an index of the degree of unevenness of the toner, and indicates 1.000 when the toner is a perfect sphere, and the average circularity becomes smaller as the toner surface shape becomes more complicated.
[0061]
In this measurement, the reason why the circularity is measured only for the particle group having an equivalent circle diameter of 3 μm or more is that the particle group of the external additive existing independently of the toner particles in the particle group having an equivalent circle diameter of less than 3 μm. This is because the circularity of the toner particle group cannot be accurately estimated due to the influence of such a large amount.
[0062]
The toner of the present invention has a weight average particle diameter of 3 to 10 [mu] m, more preferably 4 to 9 [mu] m, in order to faithfully reproduce finer latent image dots for higher image quality. In a toner having a weight average particle size of less than 3 μm, the transfer residual toner on the photoconductor increases due to a decrease in transfer efficiency, and it becomes difficult to suppress the photoconductor scraping and toner fusion in the contact charging step. Furthermore, in addition to an increase in the entire surface area of the toner, the fluidity and agitation as a powder decrease, and it becomes difficult to uniformly charge individual toner particles, so the uniformity of halftone is impaired. Sleeve ghost is also likely to occur, which is not preferable.
[0063]
On the other hand, when the weight average particle diameter of the toner exceeds 10 μm, the characters and line images are likely to be scattered and high resolution is difficult to obtain. Further, as the device becomes higher in resolution, toner of 10 μm or more tends to deteriorate the reproduction of one dot.
[0064]
In the toner of the present invention, it is important that the ratio of weight average particle diameter / number average particle diameter is 1.40 or less, more preferably 1.35 or less.
[0065]
When the ratio of weight average particle diameter / number average particle diameter is larger than 1.40, it means that the particle size distribution of the toner is wide and selective development tends to occur.
[0066]
Here, the average particle size and particle size distribution of the toner can be measured by various methods such as Coulter Counter TA-II type or Coulter Multisizer (manufactured by Coulter). In the present invention, Coulter Multisizer (manufactured by Coulter). Are connected to an interface (manufactured by Nikka) and a PC9801 personal computer (manufactured by NEC) that output the number distribution and volume distribution, and a 1% NaCl aqueous solution is prepared using first-grade sodium chloride as the electrolyte. For example, ISOTON R-II (manufactured by Coulter Scientific Japan) can be used.
[0067]
As a measuring method, 0.1 to 5 ml of a surfactant, preferably alkylbenzene sulfonate, is added as a dispersant to 100 to 150 ml of the electric field aqueous solution, and 2 to 20 mg of a measurement sample is further added. The electrolyte in which the sample is suspended is dispersed for about 1 to 3 minutes with an ultrasonic disperser, and the volume and number of toner particles of 2 μm or more are measured by using a 100 μm aperture as an aperture in the previous term Coulter Multisizer. Distribution and number distribution are calculated. Then, the volume-based weight average particle diameter (D4) obtained from the volume distribution and the number-based length average particle diameter obtained from the number distribution, that is, the number average particle diameter (D1) are obtained. The same measurement was performed in the examples described later.
[0068]
The toner of the present invention contains a release agent, but as described above, the dispersion state of the release agent also affects the developability. Therefore, when the toner of the present invention is divided into a toner (F) having a weight average particle diameter smaller than that of the toner and a toner (G) having a weight average particle diameter larger than that of the toner, the toner is subjected to differential thermal analysis ( DSC) When the heat absorption amounts of the respective toners (F) and (G) in the measurement are Hf and Hg, it is preferable that 0.60 <Hg / Hf <1.50, and 0.80 <Hg / Hf <1. .20 is more preferable. Here, the closer the Hg / Hf is to 1, the better the dispersibility of the release agent, and such a toner can be obtained by adding the treated wax in the present invention.
[0069]
A toner having Hg / Hf smaller than 0.60 has a large amount of uneven release agent, which means that there are particles containing a large amount of the release agent. Such particles are liable to deteriorate the uniformity of charging due to the exudation of the release agent on the toner surface, and to cause ghost. Further, such toner is not preferable because it tends to cause toner deterioration in long-term use.
[0070]
It is also known that generally when a release agent is contained, the chargeability of the toner is lowered, and a toner having a small particle size tends to be charged up. For this reason, if Hg / Hf is greater than 1.50, that is, when a large particle size toner contains a large amount of a release agent, the toner as a whole cannot have uniform chargeability and ghosting occurs. It tends to occur.
[0071]
Furthermore, Hg / Hf greater than 1.50 may mean that there is a relatively large free mold release agent, and the presence of such a free mold release agent only adversely affects development. Even in this case, the sleeve ghost is deteriorated and fog is increased, which is not preferable.
[0072]
In this way, it is considered that by setting 0.60 <Hg / Hf <1.50, uniform chargeability can be obtained even in long-term use, and a high-definition image without ghost can be obtained. Yes.
[0073]
As described above, low humidity can be achieved by suppressing the selective developability by setting the particle size distribution to a specific value, and the synergistic effect of dispersibility of the release agent and charging uniformity by setting the toner shape to a specific value. The sleeve ghost can be suppressed even under the environment, and a uniform halftone image can be obtained.
[0074]
The toner of the present invention may contain a charge control agent in order to stabilize the charge characteristics. As the charge control agent, known ones can be used, and a charge control agent that has a high charging speed and can stably maintain a constant charge amount is particularly preferable. Further, when the toner is produced using a direct polymerization method, a charge control agent having a low polymerization inhibitory property and substantially free from a solubilized product in an aqueous dispersion medium is particularly preferable. Specific compounds include, as negative charge control agents, metal compounds of aromatic carboxylic acids such as salicylic acid, alkylsalicylic acid, dialkylsalicylic acid, naphthoic acid, dicarboxylic acid, metal salts or metal complexes of azo dyes or azo pigments, sulfones Examples thereof include a polymer compound having an acid or carboxylic acid group in the side chain, a boron compound, a urea compound, a silicon compound, and a calixarene. Examples of the positive charge control agent include a quaternary ammonium salt, a polymer compound having the quaternary ammonium salt in the side chain, a guanidine compound, a nigrosine compound, and an imidazole compound.
[0075]
As a method of incorporating a charge control agent into the toner, there are a method of adding it inside the toner particles and a method of adding it externally. The amount of these charge control agents used is determined by the toner production method including the type of binder resin, the presence or absence of other additives, and the dispersion method, and is not uniquely limited. When added internally, it is preferably used in the range of 0.1 to 10 parts by mass, more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the binder resin. In addition, when externally added, the amount is preferably 0.005 to 1.0 part by mass, more preferably 0.01 to 0.3 part by mass with respect to 100 parts by mass of the toner.
[0076]
However, in the toner of the present invention, it is not essential to add a charge control agent, and the toner does not necessarily contain a charge control agent by actively utilizing frictional charging with the toner layer pressure regulating member or the toner carrier. There is no.
[0077]
The toner of the present invention can be prepared by preparing toners having different particle sizes, colorant and release agent contents and then mixing them, or by differently dispersing the colorant and release agent in the production stage. Is not particularly limited. However, in general, toner particles obtained by the pulverization method are irregular in shape, and in order to obtain the physical property of an average circularity of 0.970 or more, which is an essential condition of the toner according to the present invention, Productivity or inferior productivity is required and productivity is inferior. Therefore, the toner of the present invention is preferably produced in water such as a dispersion polymerization method, an association aggregation method, or a suspension polymerization method. In addition, an oil component is prepared by mixing a binder resin, a colorant, a release agent, and other additives in an organic solvent in which the binder resin is soluble, and then suspending the oil component in an aqueous medium. The toner of the present invention is preferably produced by preparing a suspension by particle formation to prepare a suspension and removing the organic solvent from the suspension. Among these, particularly in the suspension polymerization method, various physical properties as essential constituent elements of the present invention can be easily obtained, which is very preferable.
[0078]
The suspension polymerization method is a polymerizable monomer system in which a polymerizable monomer and a colorant (in addition, a polymerization initiator, a crosslinking agent, a charge control agent, and other additives as necessary) are uniformly dissolved or dispersed. After that, this polymerizable monomer system is dispersed in a continuous layer containing a dispersion stabilizer (for example, an aqueous phase) using an appropriate stirrer and simultaneously subjected to a polymerization reaction to obtain a toner having a desired particle size. To get. The toner obtained by this suspension polymerization method (hereinafter, polymerized toner) is suitable for the present invention having an average circularity of 0.970 or more and a mode circularity of 099 or more because the individual toner particle shapes are substantially spherical. It is easy to obtain a toner that satisfies the physical property requirements, and such toner has a high transferability because the distribution of the charge amount is relatively uniform.
[0079]
In the production of the polymerized toner according to the present invention, examples of the polymerizable monomer constituting the polymerizable monomer system include the following.
[0080]
Examples of the polymerizable monomer include styrene monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, and p-ethylstyrene; methyl acrylate, ethyl acrylate, Acrylic esters such as n-butyl acrylate, isobutyl acrylate, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, etc. Types; methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, Methacrylic acid dimethyl aminoethyl, methacrylic acid esters such as diethylaminoethyl methacrylate; and other acrylonitrile, methacrylonitrile, and the like monomers acrylamide. These monomers can be used alone or in combination. Among the above-mentioned monomers, styrene or a styrene derivative is preferably used alone or mixed with other monomers from the viewpoint of toner developability and durability.
[0081]
In the production of the polymerized toner according to the present invention, the polymerization may be performed by adding a resin to the polymerizable monomer system. For example, hydrophilic functional groups such as amino groups, carboxylic acid groups, hydroxyl groups, sulfonic acid groups, glycidyl groups, nitrile groups, etc. that cannot be used because monomers are water-soluble and dissolve in aqueous suspension to cause emulsion polymerization. When it is desired to introduce the polymerizable monomer component contained in the toner, it may be in the form of a copolymer such as a random copolymer of these and a vinyl compound such as styrene or ethylene, a block copolymer, or a graft copolymer. Alternatively, it can be used in the form of a polycondensate such as polyester or polyamide, a polyaddition polymer such as polyether or polyimine. When such a polymer containing a polar functional group is allowed to coexist in the toner, the above-described wax component is phase-separated, the encapsulation becomes stronger, and a toner having good blocking resistance and developability can be obtained.
[0082]
Among these resins, the effect is greatly increased by containing a polyester resin. I think this is because of the following reasons. Since the polyester resin contains many ester bonds which are functional groups having relatively high polarity, the polarity of the resin itself becomes high. Due to its polarity, polyester tends to be unevenly distributed on the surface of the droplets in the aqueous dispersion medium, and polymerization proceeds while maintaining this state, resulting in a toner. For this reason, the uneven distribution of the polyester resin on the toner surface makes the surface state and surface composition uniform, resulting in a uniform chargeability and a synergistic effect with good release agent encapsulation. Therefore, very good developability can be obtained.
[0083]
In addition, resins other than those described above may be added to the monomer system for the purpose of improving the dispersibility and fixing properties of the material or image characteristics. Examples of the resin used include styrene such as polystyrene and polyvinyltoluene. And styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, Styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene -Butyl methacrylate copolymer, styrene-dimethyl methacrylate Copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid Styrene copolymers such as copolymers and styrene-maleic acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resin, polyester resin, polyamide resin, epoxy resin Polyacrylic acid resin, rosin, modified rosin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin and the like can be used alone or in combination. As addition amount of these resin, 1-20 mass parts is preferable with respect to 100 mass parts of polymerizable monomers. If it is less than 1 part by mass, the effect of addition is small, while if it exceeds 20 parts by mass, it becomes difficult to design various physical properties of the polymerized toner.
[0084]
Furthermore, if a polymer having a molecular weight different from the molecular weight range of the toner obtained by polymerizing the polymerizable monomer is dissolved in the monomer and polymerized, a toner having a wide molecular weight distribution and high offset resistance can be obtained. I can do it.
[0085]
As the colorant used in the present invention, as the black colorant, carbon black, a magnetic material, and a color adjusted to black using a yellow / magenta / cyan colorant are used.
[0086]
When a magnetic material is used as the black colorant, it is preferably one that has been hydrophobized with a coupling agent. When hydrophobizing the surface of the magnetic material, a magnetic material obtained by surface treatment while hydrolyzing the coupling agent while dispersing the magnetic material to have a primary particle size in an aqueous medium is preferable. The hydrophobic treatment method in an aqueous medium is less likely to cause coalescence between magnetic particles compared to the treatment in the gas phase, and the repulsive action between the magnetic particles due to the hydrophobic treatment works. Since the surface treatment is performed almost in the state of primary particles, a highly uniform hydrophobicity is achieved, which is preferable.
[0087]
The method of treating the surface of the magnetic material while hydrolyzing the coupling agent in an aqueous medium does not require the use of a coupling agent that generates a gas, such as chlorosilanes and silazanes, and further, In the phase, magnetic particles can be easily combined with each other, and a highly viscous coupling agent that has been difficult to be processed can be used, so that the hydrophobizing effect is great.
[0088]
Examples of the coupling agent that can be used in the present invention include a silane coupling agent and a titanium coupling agent. More preferably used is a silane coupling agent having a general formula
RmSiYn
[Wherein, R represents an alkoxy group, m represents an integer of 1 to 3, Y represents a hydrocarbon group such as an alkyl group, a vinyl group, a glycidoxy group, or a methacryl group, and n represents an integer of 1 to 3. Show. ]
It is shown by. For example, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane, methyltriethoxysilane, isobutyltrimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethyl Mention may be made of methoxysilane, hydroxypropyltrimethoxysilane, phenyltrimethoxysilane, n-hexadecyltrimethoxysilane and n-octadecyltrimethoxysilane.
[0089]
In particular, the formula
C_pH_{2p + 1}-Si- (OC_qH_{2q + 1})_Three
[Wherein p represents an integer of 2 to 20, and q represents an integer of 1 to 3]
It is preferable to hydrophobize the magnetic substance in an aqueous medium using an alkyltrialkoxysilane coupling agent represented by
[0090]
When p in the above formula is smaller than 2, the hydrophobic treatment is easy, but it is difficult to sufficiently impart hydrophobicity. When p is larger than 20, the hydrophobicity is sufficient. The coalescence of the particles increases, making it difficult to sufficiently disperse the magnetic particles in the toner.
[0091]
On the other hand, when q is larger than 3, the reactivity of the silane coupling agent is lowered and the hydrophobicity is not sufficiently performed. In particular, p in the formula represents an integer of 2 to 20 (more preferably an integer of 3 to 15), and q represents an integer of 1 to 3 (more preferably an integer of 1 or 2). A coupling agent should be used.
[0092]
The amount of treatment is 0.05 to 20 parts by mass, preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the magnetic substance, and the treatment agent depending on the surface area of the magnetic substance and the reactivity of the coupling agent. It is preferable to adjust the amount.
[0093]
In the present invention, the aqueous medium is a medium containing water as a main component. Specific examples of the aqueous medium include water itself, water added with a small amount of a surfactant, water added with a pH adjusting agent, and water added with an organic solvent. As the surfactant, a nonionic surfactant such as polyvinyl alcohol is preferable. The surfactant is preferably added in an amount of 0.1 to 5% by mass with respect to water. Examples of the pH adjuster include inorganic acids such as hydrochloric acid.
[0094]
Stirring is sufficiently performed, for example, with a mixer having a stirring blade (specifically, a high shear force mixing device such as an attritor or a TK homomixer) so that the magnetic fine particles become primary particles in the aqueous medium. Is good.
[0095]
The magnetic particles thus obtained have no aggregation of particles, and the surface is uniformly hydrophobized, so that when used as a toner material, the dispersibility in the toner is very good, and the toner surface There is no exposure from.
[0096]
Further, the magnetic material used in the toner of the present invention may contain elements such as iron, phosphorus, cobalt, nickel, copper, magnesium, manganese, aluminum, silicon, etc., and includes oxidized iron tetroxide, γ-iron oxide, etc. It is mainly composed of iron, and these are used alone or in combination of two or more. These magnetic materials have a BET specific surface area of 2 to 30 m by the nitrogen adsorption method.²/ G is preferred, especially 3 to 28 m²/ G is more preferable. Further, those having a Mohs hardness of 5 to 7 are preferred.
[0097]
The magnetic material used in the toner of the present invention is preferably used in an amount of 10 to 200 parts by weight, more preferably 20 to 180 parts by weight, based on 100 parts by weight of the polymerizable monomer. When the blending amount of iron oxide is less than 10 parts by mass, the coloring power of the developer is poor, and it is difficult to suppress fogging. On the other hand, when it exceeds 200 parts by mass, the coercive force due to the magnetic force on the developer carrying member is increased and developability is increased. Not only makes it difficult to uniformly disperse the magnetic material into individual toner particles, but also reduces the fixability.
[0098]
As the colorant when the toner of the present invention is used as a color toner, known dyes and / or pigments are used. Examples include carbon black, phthalocyanine blue, permanent brown FG, brilliant first scarlet, pigment green B, rhodamine-B base, sorbent red 49, solvent red 146, solvent blue 35, quinacridone, carmine 6B, and disazo yellow. Can be used alone or in admixture of two or more. It is preferable that the usage-amount of a coloring agent is about 2-25 mass parts with respect to 100 mass parts of polymerizable monomers.
[0099]
As the polymerization initiator used in the production of the toner of the present invention, a polymerization initiator having a half-life of 0.5 to 30 hours is 0.5 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer. When the polymerization reaction is carried out in an added amount, a polymer having a maximum between 10,000 and 100,000 in molecular weight can be obtained, and desirable strength and suitable melting characteristics can be imparted to the toner.
[0100]
As the polymerization initiator, there are conventionally known azo polymerization initiators, peroxide polymerization initiators, and the like. As the azo polymerization initiator, 2,2′-azobis- (2,4-dimethylvaleronitrile) is used. 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisiso Examples include butyronitrile, and peroxide polymerization initiators include t-butyl peroxyacetate, t-butyl peroxylaurate, t-butyl peroxypivalate, t-butyl peroxy-2-ethylhexa Noate, t-butylperoxyisobutyrate, t-butylperoxyneodecanoate, t-hexylperoxyacetate, t-hexylperoxy Urate, t-hexylperoxypivalate, t-hexylperoxy-2-ethylhexanoate, t-hexylperoxyisobutyrate, t-hexylperoxyneodecanoate, t-butylperoxybenzoate, α , Α′-bis (neodecanoylperoxy) diisopropylbenzene, cumylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 1,1,3 3-tetramethylbutylperoxyneodecanoate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, 2,5-dimethyl-2,5-bis (2-ethylhexanoylperoxy) hexane, -Cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, t-hexyl -Oxyisopropyl monocarbonate, t-butyl peroxyisopropyl monocarbonate, t-butyl peroxy 2-ethylhexyl monocarbonate, t-hexyl peroxybenzoate, 2,5-dimethyl-2,5-bis (benzoylperoxy) hexane T-butylperoxy-m-toluoyl benzoate, bis (t-butylperoxy) isophthalate, t-butylperoxymaleic acid, t-butylperoxy-3,5,5-trimethylhexanoate, Peroxyesters such as 2,5-dimethyl-2,5-bis (m-toluoylperoxy) hexane, diacyl peroxides such as benzoyl peroxide, lauroyl peroxide, isobutyryl peroxide, diisopropyl peroxide Peroxydicarbonates such as carbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, 1,1-di-t-butylperoxycyclohexane, 1,1-di-t-hexylperoxycyclohexane, 1, Peroxyketals such as 1-di-t-butylperoxy-3,3,5-trimethylcyclohexane, 2,2-di-t-butylperoxybutane, di-t-butyl peroxide, dicumyl peroxide, Examples include dialkyl peroxides such as t-butylcumyl peroxide, and other examples include t-butylperoxyallyl monocarbonate, and two or more of these initiators can be used as necessary.
[0101]
In producing the toner of the present invention, a crosslinking agent may be added. As a preferable addition amount of a crosslinking agent, it is 0.001-15 mass parts with respect to 100 mass parts of polymerizable monomers.
[0102]
Here, as the crosslinking agent, a compound having two or more polymerizable double bonds is mainly used, for example, an aromatic divinyl compound such as divinylbenzene, divinylnaphthalene, etc .; for example, ethylene glycol diacrylate, ethylene glycol diester Carboxylic acid ester having two double bonds such as methacrylate, 1,3-butanediol dimethacrylate, etc .; Divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfone, etc .; and having three or more vinyl groups Are used alone or as a mixture.
[0103]
In the method for producing the toner of the present invention by a polymerization method, generally, the above-described toner composition or the like is appropriately added, and the polymerizability is uniformly dissolved or dispersed by a disperser such as a homogenizer, a ball mill, a colloid mill, or an ultrasonic disperser. The monomer system is suspended in an aqueous medium containing a dispersion stabilizer. At this time, the particle size of the obtained toner particles becomes sharper by using a high-speed disperser such as a high-speed stirrer or an ultrasonic disperser to obtain a desired toner particle size all at once. The polymerization initiator may be added at the same time as other additives are added to the polymerizable monomer, or may be mixed immediately before being suspended in the aqueous medium. In addition, a polymerization initiator dissolved in a polymerizable monomer or solvent can be added immediately after granulation and before starting the polymerization reaction.
[0104]
After granulation, stirring may be performed using a normal stirrer to such an extent that the particle state is maintained and the particles are prevented from floating and settling.
[0105]
When the toner of the present invention is produced, known surfactants, organic dispersants and inorganic dispersants can be used as the dispersion stabilizer. In particular, inorganic dispersants are less likely to produce harmful ultrafine powders, and because of their steric hindrance, dispersion stability is obtained, so even if the reaction temperature is changed, stability is not easily lost, and washing is easy and does not adversely affect the toner. Therefore, it can be preferably used. Examples of such inorganic dispersants include polyvalent metal phosphates such as calcium phosphate, magnesium phosphate, aluminum phosphate and zinc phosphate, carbonates such as calcium carbonate and magnesium carbonate, calcium metasuccinate, calcium sulfate and barium sulfate. Inorganic oxides such as inorganic salts, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, silica, bentonite and alumina can be mentioned.
[0106]
When these inorganic dispersants are used, they may be used as they are, but in order to obtain finer particles, the inorganic dispersant particles can be generated and used in an aqueous medium. For example, in the case of calcium phosphate, a sodium phosphate aqueous solution and a calcium chloride aqueous solution can be mixed with high-speed stirring to produce water-insoluble calcium phosphate, which enables more uniform and fine dispersion. At the same time, a water-soluble sodium chloride salt is produced as a by-product. However, if a water-soluble salt is present in the aqueous medium, dissolution of the polymerizable monomer in water is suppressed, and an ultrafine toner based on emulsion polymerization is produced. Since it becomes difficult to generate | occur | produce, it is more convenient. Since it becomes an obstacle when removing the remaining polymerizable monomer at the end of the polymerization reaction, it is better to replace the aqueous medium or desalinate with an ion exchange resin. The inorganic dispersant can be almost completely removed by dissolving with an acid or alkali after completion of the polymerization.
[0107]
These inorganic dispersants are desirably used alone in an amount of 0.2 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer. Since it is slightly weak, 0.001-0.1 part by mass of a surfactant may be used in combination.
[0108]
Examples of the surfactant include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, sodium stearate, potassium stearate and the like.
[0109]
In the polymerization step, the polymerization is performed at a polymerization temperature of 40 ° C. or higher, generally 50 to 90 ° C. When the polymerization is carried out in this temperature range, the release agent or wax to be sealed inside is precipitated by phase separation, and the encapsulation becomes more complete. In order to consume the remaining polymerizable monomer, it is possible to raise the reaction temperature to 90 to 150 ° C. at the end of the polymerization reaction.
[0110]
After the polymerization is completed, the polymerized toner particles are filtered, washed and dried by a known method, and if necessary, inorganic fine powder is mixed and adhered to the surface, whereby the toner of the present invention can be obtained. It is also possible to put a classification step into the manufacturing process and cut coarse powder and fine powder.
[0111]
In order to improve the image quality, it is preferable that a fluidity improver is externally added to the toner particles of the present invention.
[0112]
As the fluidity improver, inorganic fine powders such as silicate fine powder, titanium oxide, and aluminum oxide are preferable. The inorganic fine powder is preferably hydrophobized with a hydrophobizing agent such as a silane coupling agent, silicone oil or a mixture thereof.
[0113]
When the toner particles are non-magnetic color toner particles for forming a full color image, it is preferable to use titanium oxide fine particles as an external additive.
[0114]
Usually, the fluidity improver is used in an amount of 0.1 to 5 parts by mass with respect to 100 parts by mass of the toner particles.
[0115]
For mixing the toner particles and the external additive, it is preferable to use a mixer such as a Henschel mixer.
[0116]
When the toner of the present invention is used for a two-component developer, the toner is used by mixing with a magnetic carrier. As the magnetic carrier, for example, surface-oxidized or unoxidized iron, nickel, copper, zinc, cobalt, manganese, chromium, rare earth metal particles, alloy particles thereof, oxide particles, ferrite and the like can be used.
[0117]
The coated carrier obtained by coating the surface of the magnetic carrier particles with a resin is particularly preferable in a developing method in which an AC bias is applied to the developing sleeve. As a coating method, a method in which a coating solution prepared by dissolving or suspending a coating material such as a resin in a solvent is adhered to the surface of the magnetic carrier core particle, and a method in which the magnetic carrier core particle and the coating material are mixed with powder. A conventionally known method can be applied.
[0118]
Examples of the coating material on the surface of the magnetic carrier core particle include silicone resin, polyester resin, styrene resin, acrylic resin, polyamide, polyvinyl butyral, and aminoacrylate resin. These are used alone or in plural.
[0119]
When a two-component developer is prepared by mixing the toner of the present invention and a magnetic carrier, the mixing ratio is usually 2 to 15% by mass, preferably 4 to 13% by mass, as the toner concentration in the developer. Good results are obtained. If the toner concentration is less than 2% by mass, the image density tends to decrease, and if it exceeds 15% by mass, fogging or in-machine scattering tends to occur.
[0120]
Next, an example of an image forming apparatus that can suitably use the toner of the present invention will be specifically described with reference to the drawings.
[0121]
A 600 dpi laser beam printer (manufactured by Canon: LBP-8Mark IV) as shown in FIG. 3 was prepared as an image forming apparatus. This device has been modified so that the process speed is 80 mm / s. As shown in FIG. 3, this apparatus uniformly charges the photosensitive member 56 using a charging roller 51 to which a direct current and an alternating current component are applied. At this time, the DC component is controlled to a constant voltage, and the AC component is controlled to a constant current. Note that the conductive layer of the charging roller has a volume low efficiency of 10²Ω · cm, resistance layer is 10⁷The thing of ohm * cm was used and it set so that a contact pressure might be 230 N / m. After charging, an image portion is exposed with a laser beam 60 to form an electrostatic latent image, a toner image is formed as a visible image with a one-component nonmagnetic toner, and then a transfer roller (volume low efficiency is applied). 5 × 10⁹The toner image is transferred to the transfer material 58 by (Ω · cm) 57. The transfer material on which the toner image is placed is fixed on the transfer material by the fixing device 63. The contact pressure between the photosensitive member and the transfer roller was set to a linear pressure of 130 N / m. Further, the toner partially left on the photoconductor is cleaned by a blade made of urethane rubber as the cleaning member 59.
[0122]
As shown in FIG. 3, the developing container 52 has a toner carrier 54 as a toner supply member in contact with the photosensitive member 56. The moving direction and the rotational peripheral speed of the surface of the toner carrier 54 are the same in the contact portion with the surface of the photosensitive drum.
[0123]
As a means for applying toner to the toner carrier, an application roller 55 is provided at the developing portion and is in contact with the toner carrier. In the contact portion, the toner is applied onto the toner carrier by rotating the surface of the application roller 55 so that the moving direction of the surface of the application roller 55 is opposite to the moving direction of the toner carrier. Further, a resin-coated stainless steel blade 53 is attached for controlling the coat layer of the toner on the toner carrier. In the developing region, a DC developing bias is applied between the photoconductor 56 and the toner carrier 54, and the toner on the toner carrier flies onto the photoconductor 56 in accordance with the electrostatic latent image to become a visible image. .
[0124]
Next, an example of an image forming method for forming a full color image will be described with reference to the drawings.
[0125]
FIG. 4 shows an image forming apparatus in which toner images of respective colors are formed in a plurality of image forming units, and these are sequentially transferred onto the same transfer material. Here, the first, second, third and fourth image forming units 29 are used._a, 29_b, 29_c, 29_dAre arranged in parallel, and each image forming unit has its own electrostatic latent image holding member, so-called photosensitive drum 19._a, 19_b, 19_c, And 19_dIt has. Photosensitive drum 19_aThru 19_dIs a latent image forming means 23 on its outer peripheral side._a, 23_b, 23_cAnd 23_d, Developing unit 17_a, 17_b, 17_cAnd 17_d, The discharge part 24 for transfer_a, 24_b, 24_cAnd 24_dAnd the cleaning unit 18_a, 18_b, 18_cAnd 18_dIs arranged. With this configuration, first, the first image forming unit 29_aThe photosensitive drum 19_aOn top of the latent image forming means 23_aThus, for example, a yellow component color latent image is formed in the original image. The latent image is developed by the developing means 17._aA visible image is formed with a developer having a yellow toner, and the transfer unit 24_aThen, the image is transferred to a recording material S as a transfer material. While the yellow image is transferred to the transfer material S as described above, the second image forming unit 29_bThen, the latent image of the magenta component color is the photosensitive drum 19._bFormed on top, followed by developing means 17_bA visible image is formed with a developer having a magenta toner. This visible image (magenta toner image) is the first image forming unit 29 described above._aThe transfer material S that has been transferred at the transfer portion 24 is transferred to the transfer portion 24._bWhen transferred to the transfer material S, the transfer material S is transferred to a predetermined position. Thereafter, the third and fourth image forming units 29 are processed in the same manner as described above._c, 29_dAs a result, cyan and black images are formed, and the cyan and black colors are transferred onto the same transfer material S. When such an image forming process is completed, the transfer material S is conveyed to the fixing unit 22 and the image on the transfer material S is fixed. As a result, a multicolor image is obtained on the transfer material S. Each tourist drum 19 that has been transferred_a, 19_b, 19_cAnd 19_dIs the cleaning section 18_a, 18_b, 18_cAnd 18_dThus, the residual toner is removed and used for the subsequent latent image formation. In the image forming apparatus, a conveyance belt 25 is used for conveying the recording material S as a transfer material. In FIG. 4, the transfer material S is conveyed from the right side to the left side. Image forming unit 29_a, 29_b, 29_cAnd 29_dEach transfer section 24 in FIG._a, 24_b, 24_cAnd 24_dPass through and receive transcription. In this image forming method, a transport belt using a tetron fiber mesh as a transport means for transporting a transfer material and a thin dielectric such as a polyethylene terephthalate resin, a polyimide resin, and a urethane resin from the viewpoint of durability. A conveyor belt using a body sheet is used. The transfer material S is the fourth image forming unit 29.^dThen, the AC voltage is applied to the static eliminator 20, the transfer material S is neutralized and separated from the belt 25, and then enters the fixing unit 22, where the image is fixed, and is discharged from the discharge port 26.
[0126]
In this image forming method, each of the image forming portions is provided with an independent electrostatic latent image holding member, and the transfer material is a belt-type conveying unit, and the transfer portion of each electrostatic latent image holding member is sequentially transferred. You may comprise so that it may be sent to. In this image forming method, an electrostatic latent image holding member common to the image forming unit is provided, and the transfer material is repeatedly sent to the transfer unit of the electrostatic latent image holding member by a drum type conveying unit. It may be configured to receive the transfer of each color.
[0127]
Next, an example of an image forming apparatus capable of suitably using a magnetic toner using a magnetic material as a colorant will be specifically described with reference to the drawings.
[0128]
In FIG. 5, reference numeral 1 denotes a photosensitive drum, and a primary charging roller 5, a developing device 10, a transfer charging roller 3, a cleaner 4, and a paper feeding roller 7 are provided around the photosensitive drum. The photosensitive drum 1 is charged to −700 V by the primary charging roller 5 (applied voltages are AC voltage −2.0 kVpp, DC voltage −700 VDC). Then, exposure is performed by irradiating the photosensitive drum 1 with laser light 12 by the laser generator 6. The electrostatic latent image on the photosensitive drum 1 is developed with a one-component magnetic toner by the developing device 10 and transferred onto the transfer material by the transfer charging roller 3 in contact with the photosensitive drum 1 via the transfer material. The transfer material on which the toner image is placed is conveyed to the fixing device 9 by the conveyance belt 8 or the like and fixed on the transfer material. Further, the toner remaining on a part of the photosensitive drum 1 is cleaned by the cleaner 4. As shown in FIG. 5, the developing device 10 is provided with a cylindrical toner carrier 2 (hereinafter referred to as a developing sleeve) made of a nonmagnetic metal such as aluminum or stainless steel in the vicinity of the photosensitive drum 1. The gap between the photosensitive drum 1 and the developing sleeve 2 is maintained at about 230 μm by a sleeve / photosensitive gap holding member or the like (not shown). A magnet roller (not shown) is fixed and arranged concentrically with the developing sleeve 2 in the developing sleeve. However, the developing sleeve 2 is rotatable. The magnet roller is provided with a plurality of magnetic poles, which affect development, toner coat amount regulation, toner intake / conveyance, and toner blowout prevention, respectively. An elastic blade 13 is provided as a member for regulating the amount of magnetic toner that adheres to the developing sleeve 2 and is conveyed, and the amount of toner conveyed to the developing region is controlled by the contact pressure of the elastic blade 13 against the developing sleeve 2. . In the developing area, a DC and AC developing bias is applied between the photosensitive drum 1 and the developing sleeve 2, and the toner on the developing sleeve 2 flies onto the photosensitive drum 1 in accordance with the electrostatic latent image and is visible. It becomes.
[0129]
・ DSC measurement
It measures as follows using a differential scanning calorimeter (DSC measuring apparatus) and DSC-7 (made by Perkin Elmer).
[0130]
The measurement sample is precisely weighed in an amount of 2 to 10 mg, preferably 5 mg. This is put in an aluminum pan, and an empty aluminum pan is used as a reference, and measurement is performed at a temperature rise rate of 10 ° C./min at room temperature and normal humidity within a measurement temperature range of 30 to 200 ° C. In this temperature raising process, an endothermic peak of the main peak of the DSC curve in the temperature range of 30 to 200 ° C. is obtained.
[0131]
・ GPC measurement
The molecular weight of the chromatogram by gel permeation chromatography (GPC) is measured under the following conditions.
[0132]
The column was stabilized in a heat chamber at 40 ° C., and tetrahydrofuran (THF) as a solvent was passed through the column at this temperature at a flow rate of 1 ml / min, and the sample concentration was adjusted to 0.05 to 0.6% by mass. About 50 to 200 μl of THF sample solution is injected and measured. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts (retention time). Examples of standard polystyrene samples for preparing a calibration curve include those manufactured by Tosoh Corporation or Pressure Chemical Co. Made molecular weight 6 × 10²2.1 × 10^Three4 × 10^Three1.75 × 10^Four5.1 × 10^Four1.1 × 10^Five3.9 × 10^Five8.6 × 10^Five2 × 10⁶4.48 × 10⁶It is appropriate to use at least about 10 standard polystyrene samples. An RI (refractive index) detector is used as the detector.
[0133]
As column, 10^Three~ 2x10⁶In order to accurately measure the molecular weight region, it is preferable to combine a plurality of commercially available polystyrene gel columns, such as the combination of shodex GPC KF-801, 802, 803, 804, 805, 806, 807 manufactured by Showa Denko KK [Mu] -styragel 500, 10 manufactured by Waters^Three10^Four10^FiveCan be mentioned.
[0134]
【Example】
Specific examples of the present invention will be described below, but the present invention is not limited to these examples. The number of parts in the following formulation is parts by mass.
[0135]
(Processed wax production method)
After adding 80 g of dicumyl peroxide as a reaction initiator to 520 g of styrene monomer and 120 g of normal butyl acrylate, the mixture is added dropwise to 3280 g of heated and melted paraffin wax A with stirring and reacted for 4 hours to treat the wax 1 in one step. Got.
[0136]
A treated wax was obtained in the same manner by changing the kind of wax, the ratio of styrene monomer, the kind and ratio of unsaturated carboxylic acid monomer, the heating temperature and the like. The ratios and characteristics are shown in Tables 1 and 2.
[0137]
[Table 1]

[0138]
[Table 2]

[0139]
(Production method of hydrophobic magnetic iron oxide)
An aqueous solution containing ferrous hydroxide was prepared by mixing 1.0 to 1.1 equivalents of a caustic soda solution with respect to iron ions in an aqueous ferrous sulfate solution. While maintaining the aqueous solution at pH 8, air was blown in, and an oxidation reaction was performed at 80 to 90 ° C. to prepare a slurry liquid for generating seed crystals. Then, after adding ferrous sulfate aqueous solution so that it becomes 0.9 to 1.2 equivalent to the initial alkali amount (sodium component of caustic soda) to this slurry liquid, the slurry liquid is maintained at pH = 8, The oxidation reaction was advanced while blowing air, and the pH was adjusted to about 6 at the end of the oxidation reaction to complete the oxidation reaction. The produced iron oxide particles are washed, filtered, taken out once, re-dispersed in another water without drying, the pH of the re-dispersed liquid is adjusted, and the silane coupling agent [n-C_TenH_{twenty one}Si (OCH_Three)_Three2 parts were added to 100 parts of magnetic iron oxide and stirred sufficiently. The produced hydrophobic iron oxide particles were washed, filtered and dried by a conventional method, and then the aggregated particles were crushed to obtain hydrophobic magnetic iron oxide.
[0140]
(Toner production method)
Production of toner 1
0.1M Na in 720 parts of ion exchange water_ThreePO_FourAfter adding 450 parts of an aqueous solution and 19 parts of 1N hydrochloric acid and heating to 60 ° C., 1.0 M-CaCl₂An aqueous medium having a pH of 5.3 containing a dispersion stabilizer was obtained by adding 67.7 parts of an aqueous solution.
[0141]
78 parts of styrene
22 parts of n-butyl acrylate
0.5 parts of divinylbenzene
Saturated polyester resin 5 parts
Negative charge control agent (dialkyl salicylic acid aluminum complex compound) 1 part
10 parts of carbon black
The above formulation was uniformly dispersed and mixed using an attritor (Mitsui Miike Chemical Co., Ltd.). The monomer composition was heated to 60 ° C., and 10 parts of the treated wax 110 was added and dissolved therein, and 4 parts by mass of the polymerization initiator t-butyl-oxy-2-ethylhexanoate was dissolved therein.
[0142]
The polymerizable monomer system is charged into the aqueous medium, and 60 ° C., N₂In an atmosphere, the mixture was stirred for 15 minutes at 10,000 rpm with a TK homomixer (Special Machine Industries Co., Ltd.) and granulated. Thereafter, the mixture was reacted at 80 ° C. for 8 hours while stirring with a paddle stirring blade. After completion of the reaction, the suspension was cooled, hydrochloric acid was added to dissolve the dispersant at pH = 2 or less, the dispersant was dissolved, filtered, washed with water, and dried to obtain toner particles 1.
[0143]
100 parts of the toner particles and silica having a primary particle size of 12 nm were treated with hexamethyldisilazane and then treated with silicone oil, and the BET value after treatment was 120 m.²Toner 1 having a weight average particle diameter of 6.9 μm was prepared by mixing 1.0 part of / g hydrophobic silica fine powder using a Henschel mixer (Mitsui Miike Chemical Co., Ltd.).
[0144]
The resulting toner 1,200 g was subjected to air classification (Elbow Jet Classifier EJ-L-3: manufactured by Nippon Steel Mining) to obtain 101 g of 98 g of toner (G) of toner (F). The obtained toner (F) and (G) were each measured for the endothermic amount of the release agent, whereby Hg / Hf was 0.98. Table 3 shows the physical properties of Toner 1.
[0145]
Production of toners 2-4
Toners 2 to 4 were obtained in the same manner as in the production of toner 1 except that the treated wax 1 was changed to the treated waxes 2 to 4. Table 3 shows the physical properties of Toners 2 to 4.
[0146]
Production of toner 5
A toner 5 was obtained in the same manner as in the production of the toner 1 except that the treated wax 1 was changed to the treated wax 6. Table 3 shows the physical properties of Toner 5.
[0147]
Production of toner 6
A toner 6 was obtained in the same manner as in the production of the toner 1 except that the treated wax 1 was changed to the treated wax 8. Table 3 shows the physical properties of Toner 6.
[0148]
Production of toner 7-10
Toners 7 to 10 were obtained in the same manner as in the production of the toner 1 except that the treated wax 1 was changed to the treated waxes 11 to 14. Table 3 shows the physical properties of Toners 7 to 10.
[0149]
Production of toner 11
Toner 11 was obtained in the same manner as in production of toner 1 except that the amount of treated wax 1 was 0.7 parts. Table 3 shows the physical properties of Toner 11.
[0150]
Production of toner 12
A toner 12 was obtained in the same manner as in the production of the toner 1 except that the amount of the treated wax 1 was 31 parts. Table 3 shows the physical properties of Toner 12.
[0151]
Production of toner 13
A toner 13 was obtained in the same manner as in the production of the toner 1 except that the treated wax 1 was changed to the treated wax 5. Table 3 shows the physical properties of Toner 13.
[0152]
Production of toner 14
A toner 14 was obtained in the same manner as in the production of the toner 1 except that the treated wax 1 was changed to the treated wax 7. Table 3 shows the physical properties of Toner 14.
[0153]
Production of toners 15-16
Toners 15 to 16 were obtained in the same manner as in the production of toner 1 except that the treated wax 1 was changed to the treated wax 9 to 10. Table 3 shows the physical properties of Toners 15-16.
[0154]
Production of toner 17
A toner 17 was obtained in the same manner as in the production of the toner 1 except that the treated wax 1 was changed to the treated wax 15. Table 3 shows the physical properties of Toner 17.
[0155]
Production of toner 18
A toner 18 was obtained in the same manner as in the production of the toner 1 except that the treated wax 1 was changed to the paraffin wax A. Table 3 shows the physical properties of Toner 18.
[0156]
Production of toner 19
0.1M Na in 720 parts of ion exchange water_ThreePO_FourAfter adding 226 parts of aqueous solution and 19 parts of 1N hydrochloric acid and heating to 60 ° C., 1.0M-CaCl₂Toner 19 was obtained in the same manner as in the production of toner 1 except that 33.9 parts of an aqueous solution was added to obtain a pH = 5.3 aqueous medium containing a dispersion stabilizer. Table 3 shows the physical properties of Toner 19.
[0157]
Production of toner 20
Toner 20 was obtained in the same manner as in Toner 1 except that 10 parts of carbon black was changed to 90 parts of hydrophobic magnetic iron oxide. Table 3 shows the physical properties of Toner 20.
[0158]
Production of toner 21
100 parts of styrene / n-butyl acrylate copolymer
(Mass ratio 78/22)
Saturated polyester resin 5 parts
Negative charge control agent (monoazo dye-based Fe compound) 4 parts
10 parts of carbon black
Treatment wax 1 10 parts
The above materials are mixed in a blender, melt kneaded with a biaxial extruder heated to 110 ° C., the cooled kneaded product is coarsely pulverized with a hammer mill, and the coarsely pulverized product is finely pulverized with a jet mill. The pulverized product was subjected to air classification to obtain toner particles 20. To 100 parts of the toner particles 20, 1.0 part of silica used in the production of the toner 1 was mixed using a Henschel mixer to prepare a toner 21 having a weight average particle diameter of 8.4 μm. Table 3 shows the physical properties of Toner 21.
[0159]
Production of toner 22
The toner particles 21 obtained in the production of the toner 21 were treated twice at 6000 rpm for 3 minutes using a hybridizer to obtain toner particles 22. To 100 parts of the toner particles, 1.0 part of silica used in the production of the toner 1 was added and mixed using a Henschel mixer to prepare the toner 22. Table 3 shows the physical properties of Toner 22.
[0160]
Production of toner 23
65 parts of styrene
2-ethylhexyl acrylate 35 parts
Divinylbenzene 0.8 parts
10 parts of carbon black
8 parts of saturated polyester resin
2 parts of unsaturated polyester resin
The above formulation was uniformly dispersed using an attritor. Thereafter, the mixture was heated to 60 ° C., 10 parts of the treated wax 1 used in the production of the toner 1 and 3.5 parts of 2,2′-azobisisobutyronitrile were added and dissolved.
[0161]
Next, after heating 650 parts of an aqueous colloidal solution of 4% by mass of tricalcium phosphate to 60 ° C., 134.3 parts of the above polymerizable monomer system was added and rotated at room temperature using a TK homomixer. The mixture was emulsified and dispersed at several 10,000 rpm for 3 minutes.
[0162]
Thereafter, the reaction was performed at 85 ° C. for 10 hours while continuing stirring in a nitrogen atmosphere, and then cooled to room temperature to obtain a toner particle dispersion.
[0163]
Next, 13.0 parts of styrene, 7.0 parts of 2-ethylhexyl acrylate, 0.4 part of 2,2′-azobisisobutyronitrile, 0.2 part of divinylbenzene, and 0.1 part of sodium lauryl sulfate were added to water. The solution was added to 20 parts and dispersed using an ultrasonic homogenizer to obtain 40.7 parts of a water emulsion.
[0164]
This was dropped into the toner particle dispersion to swell the particles. Then, it stirred under nitrogen atmosphere and reacted for 10 hours at 85 degreeC. Thereafter, the suspension was cooled, washed, filtered and dried in the same manner as toner 1, and then subjected to air classification to obtain toner particles 23.
[0165]
100 parts of the toner particles 23 and 1.0 part of silica used in the production of the toner 1 were mixed using a Henschel mixer to prepare a toner 23 having a weight average particle diameter of 7.8 μm. Table 3 shows the physical properties of Toner 23.
[0166]
[Table 3]

[0167]
[Example 1]
As the image forming apparatus, LBP-8Mark IV was remodeled and the one shown in FIG. 3 was used.
[0168]
The potential of the electrostatic charge image carrier was set to dark part potential Vd = −580V and light part potential VL = −150V. Further, as a toner carrier, a medium resistance rubber roller (diameter 16 mm, hardness ASKER C 45 degrees, resistance 10) made of silicone rubber in which carbon black is dispersed and resistance is adjusted.^Five(Ω · cm) was used to contact the photoreceptor. The developing contact width at this time was set to about 3 mm. The peripheral speed of the toner carrier was 150% (120 mm / sec) in the forward direction with respect to the peripheral speed of the photoreceptor (80 mm / sec). An application roller made of foamed urethane rubber was provided as a toner application member and brought into contact with the toner carrier. A voltage of about −550 V was applied to the coating roller. Further, a stainless steel blade coated with resin as a toner regulating member was brought into contact with a linear pressure of 39.2 N / m (40 g / cm). Further, the applied voltage at the time of development was only a direct current component (−450 V).
[0169]
The applied voltage during charging and charging was a direct current component (-1.2 kV), and the applied voltage during transfer was a direct current component (-1.5 kV).
[0170]
First, 100 g of toner 1 is filled in a cartridge, and the image is composed of only a horizontal line with a printing rate of 3% in a normal temperature and humidity environment (23 ° C., 60% RH) and a low temperature and low humidity environment (15 ° C., 10% RH). 6000 images were printed using the pattern. As a transfer material, 75 g / m²Paper was used.
[0171]
As a result, the toner 1 showed high transferability at the initial stage and after image output of 6000 sheets, no ghost, and a good image excellent in halftone reproducibility without fogging on the non-image area. . Moreover, it was excellent in low-temperature fixability and hot offset resistance, and was able to take a wide fixing temperature range. Table 4 shows the evaluation results under a normal temperature and humidity environment, and Table 5 shows the evaluation results under a low temperature and low humidity environment.
[0172]
The evaluation items described in the examples of the present invention and the comparative examples and the judgment criteria thereof will be described.
[0173]
<Fixing temperature range>
A fixing test was conducted using a modified LBP-8Mark IV machine. The image area ratio at this time is 25%, and the applied toner amount per unit area is 0.7 mg / cm.²Set to. The fixing start temperature and offset start temperature are measured by adjusting the set temperature of the fixing device every 5 ° C. within a temperature range of 120 to 210 ° C., and outputting a fixed image at each temperature. 4.9 kPa (50 g / cm²The fixing temperature at which the density reduction rate before and after the rubbing was 10% or less was determined as the fixing start temperature. Further, the set temperature was further raised from the fixing start temperature, and the temperature at which the high temperature offset occurred was determined as the offset start temperature.
[0174]
<Transfer efficiency>
The transfer efficiency is determined by taping the transfer residual toner on the photoconductor after the solid black image is transferred with a Mylar tape and pasting it on the paper. The Macbeth density value is C, and the Mylar is applied on the paper with the toner after the fixing before the transfer. When the Macbeth concentration of the tape was affixed to D and the Macbeth concentration of the Mylar tape affixed on unused paper was assumed to be E, it was approximately calculated by the following formula.
[0175]
[Expression 2]

[0176]
The transfer efficiency obtained from the above calculation results was judged according to the following criteria.
A: Transfer efficiency is 96% or more.
B: Transfer efficiency is 92% or more and less than 96%.
C: Transfer efficiency is 89% or more and less than 92%.
D: Transfer efficiency is less than 89%.
[0177]
<Fog>
The fog was measured using a REFECTMETER MODEL TC-6DS manufactured by Tokyo Denshoku. The filter used was a green filter, and fog was calculated from the following formula.
[0178]
Fog (reflectance) (%) =
Reflectivity on standard paper (%)-Reflectance of sample non-image area (%)
[0179]
The criteria for fogging are as follows.
A: Very good (less than 1.5%)
B: Good (1.5% or more to less than 2.5%)
C: Normal (2.5% or more to less than 4.0%)
D: Poor (4% or more)
[0180]
<Ghost>
The ghost criterion is that the image shown in FIG. 1 is output and visually judged according to the following criteria.
A: No ghost is generated.
B: Although a slight ghost is generated, a good image is obtained.
C: Although the ghost is generated, there is no problem in practical use.
D: Image with poor ghost and unpreferable for practical use.
[0181]
<Image quality>
The image quality criterion is a comprehensive evaluation of image uniformity and fine line reproducibility. The uniformity of the image is determined by the uniformity of the solid black image and the halftone image.
A: A clear image excellent in fine line reproducibility and image uniformity.
B: A good image although the fine line reproducibility and image uniformity are slightly inferior.
C: An image having no problem in practical use.
D: An image unfavorable for practical use due to poor fine line reproducibility and image uniformity.
[0182]
  Example 24, 8-14 and Reference Examples 3, 5-7]
  As toners, toners 2 to 12, 22, and 23 were used, and an image printing test and durability evaluation were performed under the same conditions as in Example 1. As a result, there were no problems in the initial image characteristics, and no problem was obtained in all of the 6000 sheets printed. Table 4 shows the evaluation results under a normal temperature and humidity environment, and Table 5 shows the evaluation results under a low temperature and low humidity environment.
[0183]
Example 15
As the image forming apparatus, LBP-1760 was remodeled and the one having the structure shown in FIG. 5 was used.
[0184]
The electrostatic image carrier (photosensitive drum 1) has a dark portion potential V._d= -650V, bright part potential V_L= -130V. The gap between the electrostatic charge image carrier and the developing sleeve is 270 μm, and the surface of the toner carrier is blasted with a resin layer having a layer thickness of about 7 μm and a JIS centerline average roughness (RA) of 1.0 μm. A developing sleeve formed on an aluminum cylinder having a diameter of 16φ is used, and a developing magnetic pole of 85 mT (850 gauss), a urethane regulating blade having a thickness of 1.0 mm and a free length of 0.5 mm as a toner regulating member is 39.2 N / m (40 g). / Cm).
100 parts of phenolic resin
90 parts of graphite (particle size approx. 7μm)
10 parts of carbon black
[0185]
Next, a DC bias component V as a developing bias_dc= -450V, superimposed AC bias component V_pp= 1600 V, F = 2200 Hz was used. The peripheral speed of the developing sleeve was 110% (103 mm / sec) in the forward direction with respect to the peripheral speed of the photosensitive member (94 mm / sec). The transfer bias was set to 1.5 kV DC.
[0186]
As a fixing method, there was used a fixing device of LBP-1760 which does not have an oil application function and which is fixed by heating and pressing with a heater through a film. At this time, a pressure roller having a fluororesin surface layer was used, and the diameter of the roller was 30 mm. The fixing temperature was set to 180 ° C. and the nip width was set to 7 mm.
[0187]
The fixing temperature range was evaluated in the same manner as in Example 1 except that the fixing device was used.
[0188]
The cartridge is filled with 100 g of toner 20 and is 6000 in an image pattern consisting of only a horizontal line with a printing rate of 3% in a normal temperature and humidity environment (23 ° C., 60% RH) and a low temperature and low humidity environment (15 ° C., 10% RH). The image drawing test was performed. As a transfer material, 75 g / m²Paper was used.
[0189]
As a result, the toner 20 showed high transferability at the initial stage and after image output of 6000 sheets, no ghost, and a good image excellent in halftone reproducibility without fogging to the non-image area. . Moreover, it was excellent in low-temperature fixability and hot offset resistance, and was able to take a wide fixing temperature range. Table 4 shows the evaluation results under a normal temperature and humidity environment, and Table 5 shows the evaluation results under a low temperature and low humidity environment.
[0190]
[Comparative Examples 1-8]
Toners 13 to 19 and 21 were used as toners, and an image printing test and durability evaluation were performed under the same conditions as in Example 1. As a result, transfer efficiency decreased, fogging, ghosting, and image quality deteriorated along with the durability test. Further, for toners 14, 15, and 17, the fixing temperature range was narrow.
[0191]
[Table 4]

[0192]
[Table 5]

[0193]
【The invention's effect】
By using the toner of the present invention, excellent low-temperature fixability and anti-offset properties, good toner performance is maintained even when many sheets are used, and high-definition images free from ghosting and fogging are stably provided for a long period of time. I can do it.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram of a ghost generated on an image.
FIG. 2 is a conceptual diagram of a peak area (1) on the polymer side and a peak area (2) on the low molecule side.
FIG. 3 is a diagram illustrating an example of an image forming apparatus suitable for carrying out the present invention.
FIG. 4 is a diagram illustrating an example of an image forming method for forming a full-color image.
FIG. 5 is a diagram illustrating an example of an image forming apparatus that can preferably use magnetic toner.
[Explanation of symbols]
51 Charging roller (contact charging member)
52 Development Device
54 Development sleeve (toner carrier)
55 Stirring member
56 Photoconductor (image carrier, charged member)
57 Transfer roller (transfer member)
59 Cleaner
63 Fixing device

Claims (16)

A toner having at least a binder resin, a colorant, and a release agent and having a weight average particle diameter of 3 to 10 μm;
The toner has an average circularity of 0.970 or more;
The endothermic peak in the differential thermal analysis (DSC) measurement of the release agent is in the range of 45-120 ° C;
The release agent is a paraffin wax treated with at least a styrenic monomer (hereinafter referred to as a treated wax), and the treated wax has a molecular weight determined by gel permeation chromatography (GPC) of a soluble content of tetrahydrofuran (THF). When the measurement has two peaks, the peak area on the polymer side is (1) and the peak area on the low molecule side is (2), the area ratio is
0.2 ≦ (2) / ((1) + (2)) <0.5 (Formula 1)
A toner characterized by satisfying   The toner according to claim 1, wherein an endothermic peak in a differential thermal analysis (DSC) measurement of the release agent is in a range of 50 to 90 ° C.   The toner according to claim 1, wherein the mode circularity of the toner is 0.99 or more.   4. The toner according to claim 1, wherein in the particle size distribution of the toner, a ratio of weight average particle diameter / number average particle diameter is 1.40 or less.   The number average molecular weight (Mn (1)) of (1) is 8,000 or less and the number of (2) as measured by gel permeation chromatography (GPC) of the soluble content of tetrahydrofuran (THF) in the treated wax. The toner according to claim 1, wherein the average molecular weight (Mn (2)) satisfies 200 or more. In the measurement of molecular weight by GPC of the THF soluble content of the treated wax, Mn (1) and Mn (2) are represented by the following formula:
1000 ≦ (Mn (1) −Mn (2)) ≦ 6000 (Formula 2)
The toner according to claim 1, wherein: Mn (2) is determined by GPC molecular weight measurement of THF soluble content of the treated wax, and the following formula 200 ≦ Mn (2) <2000
And the amount of the wax component graft-modified with at least a styrenic monomer among the wax components having a molecular weight of Mn (2) in the molecular weight measurement by GPC of the THF-soluble component of the treated wax. When the amount of the unmodified wax component is B, the following formula: 0.08 ≦ {B / (A + B)} × {(2) / ((1) + (2))} ≦ 0.78
The toner according to claim 1, wherein the toner satisfies the following conditions. Mn (2) is determined by GPC molecular weight measurement of THF soluble content of the treated wax, and the following formula 200 ≦ Mn (2) <2000
And the amount of the wax component graft-modified with at least a styrenic monomer among the wax components having a molecular weight of Mn (2) in the molecular weight measurement by GPC of the THF-soluble component of the treated wax. When the amount of the unmodified wax component is B, the following formula: 0.1 ≦ {B / (A + B)} × {(2) / ((1) + (2))} ≦ 0.78
The toner according to claim 1, wherein the toner satisfies the following conditions.   The toner according to claim 1, wherein the treated wax is contained in an amount of 1 to 30 parts by mass with respect to 100 parts by mass of the binder resin. The toner according to any one of claims 1 to 9, wherein the treated wax is treated with 5 to 100 parts by mass of a styrenic monomer with respect to 100 parts by mass of paraffin wax. The toner according to claim 1, wherein the treated wax is obtained by treating paraffin wax with at least a styrene monomer and an unsaturated carboxylic acid monomer. The treatment wax for paraffin Nwa box 100 parts by weight, and treated in total 5 to 100 parts by weight of styrene monomer and an unsaturated carboxylic acid monomers, (styrene monomer mass parts / unsaturated carboxylic acid-based monomer The toner according to claim 11, wherein the toner has a mass part) of 1 to 20. Each of the toners (F) and (G) when the toner (F) is divided into a toner (F) having a particle diameter smaller than the weight average particle diameter of the toner and a toner (G) having a weight average particle diameter larger than the toner. When the endothermic amount in the differential thermal analysis (DSC) measurement of the release agent is Hf, Hg,
0.60 ≦ Hg / Hf ≦ 1.50 (Formula 3)
The toner according to any one of claims 1 to 12, characterized by satisfying the. The endothermic amounts Hf and Hg are 0.80 ≦ Hg / Hf ≦ 1.20 (Formula 4)
The toner according to any one of claims 1 to 12, characterized by satisfying the. A toner prepared in a wet manner containing at least a binder resin, a colorant and a release agent;
The toner has a weight average particle diameter of 3 to 10 μm;
The toner has an average circularity of 0.970 or more;
The endothermic peak in the differential thermal analysis (DSC) measurement of the release agent is in the range of 45-120 ° C;
The release agent is a paraffin wax treated with at least a styrenic monomer (hereinafter referred to as a treated wax), and the treated wax has a molecular weight determined by gel permeation chromatography (GPC) of a soluble content of tetrahydrofuran (THF). When the measurement has two peaks, the peak area on the polymer side is (1) and the peak area on the low molecule side is (2), the area ratio is
0.2 ≦ (2) / ((1) + (2)) <0.5 (Formula 1)
A toner characterized by satisfying The toner according to claim 15 , wherein an endothermic peak in a differential thermal analysis (DSC) measurement of the release agent is in a range of 50 to 90 ° C.

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